Windows 8 and Windows 8 RT - Issues and Workarounds to get Windows 8.1 behaviour

Getting around Window 8's issues

By Strictly-Software

I use Windows 8.1 (proper version - thank god) but if you are stuck on Windows 8 or the Windows 8 RT version you should upgrade to Windows 8.1 ASAP as the design of Windows 8 was so that they could use the same display format for both phones, tablets, PC's and laptops.

The problem was that the techies didn't want numptified hidden away features behind a design obviously meant for touch screens and not for coders.

So they introduced Windows 8 RT which was a sort of half way house between Win 8.1 and Win 8 as they realised they were going to have another Vista issue where people hated the OS and many skipped over it or stayed with the previous version anyway Windows XP (I know I did!).

So when they realised they had another Vista/XP issue on their hands they rolled out Win 8 RT which tried to get rid of the main tablet screen and have am option to get back to a normal desktop screen.

Windows 8.1 was a total reverse of Windows 8 with the desktop as the main screen and the horrible tablets accessible by the home button.

As the article says:

If your PC is currently running Windows 8 or Windows RT, it's free to update to Windows 8.1 or Windows RT 8.1. And unlike previous updates to Windows, you'll get this update from the Windows Store.

by following this Windows Knowledge Base article: upgrade from Windows 8.0 or 8.1 RT to Windows 8.1.

Making some changes

The first thing I hated about the OS was that the mouse would change the size of the screen without me asking it to. In Chrome or elsewhere I was constantly manually putting the screen size back to normal ratio 100%.

In fact the mouse was moving so fast I couldn't hardly see it and I needed to make some changes. The list below are those I made.

Increasing the size and changing the colour of the mouse

I changed the colour of the mouse using the "Pointers" tab where you can pick the group of pointers you want to use to "Windows Black (extra large)" in the top selection and in the bottom I chose "Normal Select".

     

Now I could see the cursor much easier due to the colour change as most programs have a white background so a white cursor with a black border is not very helpful.

Changing the auto drag that the mouse does

One of the annoying things about Windows 8+ is the auto drag ability of the mouse which enables you to highlight or drag features without using the CTRL key.

You can turn this off in the "Buttons" > "Click Lock" panel by de-selecting the "Turn on Click Lock" feature.

This was one of the major pains I had when I first used Windows 8.1 especially when I was remote desktopped into my work PC. Then I found a way to turn it off.

Changing the mouse controlling the size of the screen

This is one thing that really pissed me off. When I was surfing the net or just writing a swipe of the mouse would change the whole screen size.

Other Mouse Changes

I also did the following changes in the "Pointer Options" tab I changed the pointer speed to a slower one.

With a bigger black pointer it helps a lot. I also did the following.

• I chose to "Automatically move pointer to default selection in a dialogue box". No point hunting for CTRL keys is there! 
• I chose to "Show location of the pointer when the CTRL key is hit" 
• A nice circle appears helping you find the cursor. 
• I disabled the "Hide pointer when typing" option so that I can always see the cursor.

Other Windows 8.1 Programs

With all the numptyfictation going on with the Windows tablet format there are some actual applications that can help you without going command line.

Even though the start bar is pretty crap you can either use the "Search" function to find an app or just go into the app page and start typing. The words will just start to appear in a search box in the top right of the page e.g "Paint" to get the Paint application.

The Windows App Store is one of the great features that Windows 8 has introduced and there are lots of great programs you can download for free including "Live TV" to get TV from freeview channels as well as US and European TV shoes.

With WiFi and network connectivity you want to check that your broadband speed is fast and everything is okay. One of these programs is "Network Speed Test" which you can get from the App Store.

This application tests your broadband or WiFi speed and tells you whether you would have the capabilities of downloading high or low quality video, your internet status, network details and other ISP related information.

So now you know how to get Windows 8.1 features, change some annoying ones in the OS related to mouse usage and use the Windows App Store to download apps to test your WiFi for you.

You should now be on your way.

Use Blogger to create blogs quickly and automate the content easily

Using Google's blogger.com over wordpress.com

Whereas blogger used to be pretty basic since the new format of blogger arrived on the free blog scene it has been much easier and quicker to set up a blog than other free CMS systems and I would recommend using the new blogger.com system over the free hosted wordpress.com site any day.

Obviously having your own server and your own code running on it is the best way to go but if you are trying to get a blog up quickly or want to automate it by sending posts by emails then I would say blogger.com is better than wordpress.com because of its new simplistic design and ease of use and for a number of other reasons.

Whereas in Wordpress you have to use a plugin (which you cannot use on their free version) to post articles by email to the site e.g Postie in blogger it is built in.

As blogger only uses tags and not categories it is a shame they cannot either have an Automatic Tagging widget like my own or allow you to post tags in the subject line as you can when you send the email.

This is possible in the Wordpress plugin Postie (available for the non hosted version)  which needs a fix to get it working properly: Fixing Postie to use Categories

But as we are talking about the free blogging versions they both have downsides on the the automated posting front.

I have a number of horse racing sites that are on my own server and also use blogger e.g:

http://ukhorseracingstar.blogspot.co.uk/
http://ukhorseracingautobot.blogspot.co.uk/


However before I created UK Horse Racing Star I tried to create a Wordpress free blog on their wordpess.com setup page to use their free domain e.g something like: ukhorseracingstar.wordpress.com.

The registration process went through okay including double email confirmation but when I tried to login it either allowed me to login but not post any articles or change settings OR it just wouldn't let me login in the first place.

During sign up it didn't say "This user name or URL is unacceptable" or that "this goes against our Terms of Service" (for whatever reason), and it really should have done if certain words are unacceptable to their Terms. If they know a word is banned from their URL's then why not say so at registration time?


On one day I tried creating 4 sites all with different names and they were all blocked with no reason given either by email (when I tried complaining) or by their system. Not good service at all.

If you go to https://signup.wordpress.com/signup/ now and try and create a blog with the name ukhorseracingstar it will say "Sorry that site already exists" and it does - by me along with 3 other variations - although I cannot use any of them!

Therefore I tried the new blogger system.

I know this strictly-software.com blog is using the old layout but I haven't got round to changing the styling -  I'm a developer not a designer or CSS guru!

However with the new blogger template and layout tools it was so easy to create a new site I had UK Horse Racing Star up in minutes with widgets down the side for links, RSS Feeds of racing results, banners, text and scripts.

It really was a very simple process to re-size uploaded images, change the background colour, add custom CSS and script.

Therefore I don't know if it's against Wordpress rules to have sites related to horse racing but if you have your own copy of the software you can do what you want with it (GPL and all that) so I have a Wordpress site hosted on my own server www.ukhorseracingtipster.com which is almost ready to rumble.

Also as wordpress.com won't even let you show Google AdSense on their free blog system OR it seems let you create sites with certain words in it like "horse" or "racing" (and whatever else is in their ban list) then I would recommend blogger for free blog hosting because you can show adverts (on non adult themed sites - e.g not gambling or porn sites - I know from my warning by Google over this so be warned)

Their new system is so simple and easy to use you can get a good looking site up in minutes and it took me less than 20 minutes to create both of these blogs:

http://ukhorseracingstar.blogspot.co.uk/
http://ukhorseracingautobot.blogspot.co.uk/ 

Whereas on wordpress.com's free blogging system it really is a very cut down version of their downloadable software and you cannot add your own images, css, scripts, widgets or plugins etc on blogger.com you can do all of this and more. Hopefully they will be extending their widget selections in the future to add more features and drag n drop functionality to their system.

So there is my two pence on the wordpress.com versus blogger.com debate.

Overcoming the Demand 5 TV Catchup Performance Problem

Solving the Demand 5, Flash Movie problem - and other Catch Up TV website issues

If you are from the UK then you may often like to catch up on missed TV programmes by watching the online TV catch up services such as BBC iPlayer, Channel Four's 4OD and Channel 5's TV Catch Up service called Demand 5.

The past few nights I have been trying to catch up on a number of programmes shown on Channel 5 as for some reason Five Star has stopped showing the latest episode of Burn Notice on a Sunday afternoon and I like to watch other shows (when they are available) like NCIS and The Mentalist etc so I try to use Channel 5's catch up website Demand 5.

I really wish they would buy the rights to show for longer so that you could watch a programme for more than just 7 days but then it's not called catchup TV for nothing and most TV programmes are made in the USA.

However when I use the Demand 5 website to watch the programme I experience a very annoying problem which effects every browser and computer I tried using including Chrome, FireFox, Safari and IE 8 on a Sony Vaio Windows XP 32 bit Dual Core and IE 9 on a Dell Windows 7 64 bit Quad core.

The Demand 5 catchup TV problem means that pre-show adverts play fine and then after a period of anything between a few seconds and a couple of minutes of the actual show playing the Demand 5 Catchup TV programme would either just freeze up and not start playing again at all. 

Or it would play for a while before stopping for a few seconds as if it was buffering more content before playing for another few seconds again - totally unwatchable.

I couldn't even move the skip bar backwards or forward and the pause / play button just didn't work at all.

A refresh would reload the page, show the adverts before the programme again and then the problem would re-occur. It was all very annoying..

After a number of seemingly ignored comments to Demand 5 complaining about them not fixing the problem and after reading on almost every show on the site that a large number of other people have had similar problems I tried solving the issue myself.

If you go to any show on Demand 5 and read the comments at the bottom e.g www.channel5.com/shows/ you will see comments along the following lines.

"Really poor transmission of episode 23. Can't get more than 20 seconds of coherent dialogue and then it freezes"

"Impossible to watch because of the poor service from Demand Five's website. Even worse than Karen's experience."

"Why is demand 5 not working? It hasn't worked for several weeks. You don't get this with iplayer!!!"

"doesnt seem to be able to play anything"

"wow the longest i got to watch before it froze was 50sec. i did give up 5min in though. I'm with sue off to iplayer which works."

And those are just a snapshot of the many comments on a couple of shows I wanted to watch today all complaining about the Demand 5 website video freezing or not playing at all. 

Demand 5 really need to fix this problem if they want to keep visitors coming to the site.

Due to my own comments and complaints not being answered I tried fixing the problem with Demand Five freezing myself - only because I really wanted to watch the latest episode of NCIS.

I wasn't going to step through all their custom JavaScript and I have no idea what they are doing server side so proper debugging is out of the question but what you can do in situations like this is turn everything else off and then back on again one by one to see if any section of the browser or website is causing the problem.

So without knowing whether they are running some client side code constantly that rewrites the DOM such as many sites try to use to beat all the plugins that are designed to hide adverts, images and flash I could try to see if turning off those parts of the site helped as they maybe running code to constantly re-insert adverts into the HTML to replace any removed by plugins like AdBlocker.

If they were doing something like this (and I don't know if the are) then it's possible that a race condition might occur between Demand 5's own advertising code and any any plugins or virus checkers (which have built in anti-banner options) that constantly scan and rebuild the DOM.Only proper debugging will prove if that is happening,

Debgging the Demand 5 website Performance Problem

So to get a fix for the the Demand 5 problem as soon as possible the first thing I did were all the normal things that developers try when met with similar issues. If you find similar problems on other sites or with plugins for websites you should always try this list first to rule them out as reasons for the problem.

• Disabling all cookies - the Web Developer Toolbar in Firefox is great for this and if you are not signing into the website there is no need for cookies to be enabled anyway.
• Disabling Java - Most websites don't even use Java Applets any-more so its not really needed until you find a site that actually makes use of it.
• Disabling JavaScript - Most websites that show TV content actually require JavaScript to be enabled for their site to work at all even though a basic Flash OBJECT or VIDEO element on a page outputted with server side code playing a movie doesn't require it. However companies like Demand 5 or iPlayer don't do this because it mean their content can easily be stolen or watched overseas by non UK citizens etc so JavaScript is actually required to load in the adverts and programming in chunks.
• Turn off all Flash tracking by disabling Flash cookies. You do this by right clicking on a flash movie, click the Global Settings option and then choose "Block all sites from storing information on this". Unless you really want another way for advertisers and websites to track your online movements there is little need for this option to be enabled. You may want to check your video and microphone options as well.

Even after all this the Demand 5 flash videos were still having problems playing and although the options I just disabled are worth doing anyway to prevent online tracking by advertisers it didn't fix the Demand 5 TV catch up problem.

Flash is a well known CPU killer on websites and I have seen whole PC's crash due to one to many flash object on a web page being left open too long. Just open a page with a few flash movies and watch the CPU rise in your task manager if you want proof - Chrome seems particularly bad for this but despite this many sites continue to try and write their whole website in Flash which is a BAD IDEA!

However I did notice that the page that held the movie also contained a large number of other banner adverts that used both flash and animated gifs and I wondered whether there was some sort of problem occurring due to all the techniques advertisers now use to try and overcome advert blockers.

Basically websites or plugins use a timer to re-insert banners that have been removed from the HTML DOM by advert blocking plugins like AdBlocker which also uses a timer to remove any adverts re-inserted this way. Both sets of code doing the opposite to each other every split second - not good for performance!

Because both the advertiser and blocker are using the same methods to scan and modify the DOM constantly it basically turns it into one big performance nightmare in which your DOM is constantly being re-written on the fly. The less client code that runs the better KISS IT (Keep It Simple Stupid) for a multitude of reasons.

The Fix for the Demand 5 website Performance Problem

I opened Firefox and went to install a plugin I use on my other computer called Flash Blocker but I noticed a new plugin had been released called Image and Flash Blocker 0.7. I thought I would try it out.

At first I thought something hadn't loaded as I couldn't see any options under my Tools menu however you need to use the context menu (right click the mouse button) to use the add-on and see the various options.

Choose "Image and Flash Blocker" from the context menu and then select "Images off, Flash off" and hey presto most of the imagery, banner adverts, flash banners and movies disappear.In fact most of the Demand 5 page is blank without these features enabled.

The flash movies are replaced with a little red circle with a white "F" (for Flash) in the middle and if you want that particular flash movie to appear you just click it.

I turned every image and flash movie off on the latest episode of the show I wanted to watch e.g Burn Notice, NCIS, Archer, The Mentalist etc, and then I clicked the main movie screen to turn the video back on.

When the adverts had finished playing the TV show played without a single stall, stoppage or flicker. Hey presto problem solved! Big slap on the back for moi.

Remember - too much whizz bangery can cause performance issues

Remember images, Applets, Active-x objects, Flash and all the other fancy whizz bangery that comes with HTML 5, CSS 3 and modern JavaScript libraries is all well and good but more often that not it can cause a massive performance overhead on your computer. The best tactic is to turn it all off and then only turn on what you need once you know you need it and the clients browser supports it.

In the case of fixing Demand 5 catch-up TV it was definitely a case of less the better as it seemed that too much was going on behind the scenes to allow their TV shows to play smoothly. What exactly is happening I don't know without access to their source code but this is definitely a workaround for the Demand 5 performance problem that works!

Hopefully this blog article will help others overcome the same problem. I have tried writing comments with a link to this article on most of the shows I watch as they all contain similar complaints but for some reason they don't like the fact I put a link into my comment or try to help people solve their own technical issues.

So if you watch Demand 5 and have performance problems remember - turn off images and flash and then turn on the only flash movie you need - the TV programme you are trying to watch and then enjoy it without any flickering or stopping every 20 seconds.

Regular Expression functions for reformatting content for Wordpress

Using RegEx to reformat Wordpress content

If you read my blog you will know I am "Mr Automate" and I specialise in scraping, reformatting, spinning and automatically posting content to Wordpress, Twitter and other sites.

I use Wordpress for a couple of my blogs and because the well known plugin WP-o-Matic has stopped being supported and the only replacements are paid for plugins like WP Robot I have basically written my own custom version to handle my automated content imports.

A couple of useful Regular Expressions you might like to use which I find particular helpful are below.

I am using PHP as that is the language Wordpress is written in but the core Regular Expressions should be easily transferable between languages.

1. Removing IFRAMES

As YouTube has moved from it's old OBJECT / EMBED nested tag soup to an IFRAME many feeds containing videos will now contain IFRAME's which need to be handled correctly as we all know that viruses can be transfered through rouge IFRAME content.

If you are just importing content from a feed without parsing and checking it then just imagine if for whatever reason the feed you are using one day contains an IFRAME with a SRC pointing to a dodgy virus infected URL. If you don't sanitize the content you will be inserting this dangerous content into your own blog for your visitors to become infected by.

Although most modern browsers and virus checkers are good at picking up on potential malicious URL access it is always wise to run your own checks using a white list of "allowed" domains rather than a "black list" of banned ones.

This code is a basic example of looping through all the IFRAMES on a page, checking their SRC tag for a known white list of acceptable domains and then replacing any IFRAME's that don't match.

// match all XHTML IFRAME tags where $content holds your HTML
$videocount = preg_match_all("@(<iframe[\s\S]+?<\/iframe>)@",$content,$videos,PREG_SET_ORDER);

foreach($videos as $video){

 $object = $video[1];

 // only allow certain domains e.g youtube, dailymotion, vimeo, cnn, fox, msnbc and the bbc
 if(!preg_match("@src=['\"]http:\/\/(www\.)?(?:youtube|dailymotion|vimeo|cnn|fox|msnbc|bbc)\.@i",$object)){
  
  // replace the IFRAME as we don't know where it is pointing to

  $content = preg_replace("@" . preg_quote($object) . "@","",$content);
 }
 
}

2. Re-sizing images

I have already written an article about how you can use regular expressions and a callback function to reformat videos or images so that they fit your template and this follows that theme.

PHP like Javascript and other decent languages offers the ability to create anonymous (unnamed) functions on the fly to be used as callbacks in regular expression replace functions.

Passing a function as a parameter within another function is known as a lambda function and this is very useful in certain situations such as parsing HTML where you want to remove illegal tags and attributes.

This example is pretty niche to my own needs but the idea is useful and can easily be converted to your own reformatting needs.

Basically I show little Google Adsense box adverts at the top right of all my articles and as these are floated to the right I don't want any images within my articles that are less than the size of my content area (minus the size of the advert) to also be aligned to the right as this causes a horrible looking mess.

Therefore I use this code to ensure that the Wordpress class "alignleft" is always inserted on the first image in any article but only if the width of the image is less than 350px. It doesn't matter if the image isn't right at the top of the article (although they usually are) but it helps to ensure a smooth flow and layout.

The Preg_Replace function in PHP is nice in that you can limit the number of replacements to one or more if you so wish and in this case I only want to reformat the first image. You will see that the lambda function I use also contains multiple other regular expressions and there is nothing stopping you from writing complex code within these anonymous functions.

$content = preg_replace_callback("@(<img[^>]+?class=['\"])([\s\S]*?)(['\"][\s\S]*?>)@i",
  create_function(
  '$matches',
  'preg_match("@width=[\'\"](\d+)[\'\"]@",$matches[0],$widthmatch);
  $chk=true;
  if($widthmatch){       
   if(is_numeric($widthmatch[1])){
    if($widthmatch[1] >= 350){         
     $chk = false;
    }       
   }
  }
  if($chk && !preg_match("@alignleft@",$matches[2])){
   $res = $matches[1] . trim( preg_replace("@alignright@","",$matches[2]) . " alignleft") .$matches[3];
  }else{
   $res = $matches[1] . preg_replace("@alignright@","",$matches[2]) .$matches[3];
  }
  return $res;'),$content,1);

As you can see the lambda anonymous function carries out the following logic

• It looks for the first image that has a class attribute on it and passes the match collection into the anonymous function.
• It then checks the image for a width attribute using another regular expression.
• If found it then checks that the value of the width attribute is numeric and if so it tests to see if the value is over my allowed limit of 350px setting a flag if so.
• I then use another regular expression to test for the existence of the standard Wordpress class "alignleft" and if it isn't found then I add it in making sure to replace any "alignright" class if it exists.
• The lambda function then returns the new reformatted content of the image which is then used as the replacement value in the Preg_Replace function.

Just two useful examples which can be expanded upon by anyone interested in Regular Expressions and AutoBlogging.

Remember if you require any custom plugin work for Wordpress, including special reformatting functions, scraping code or content automation then contact me for a quote.

Broken Apple Touch Icon Images

iPhone Touch Icon LINK tag doesn't work

I recently created an iPhone friendly webpage so that I could access certain stats from one of my websites on my iPhone .

The page was in a subfolder off the main website which was only half related to the stats I wanted to show. Therefore when I created the icon I wanted to use for the Home Screen I used a LINK element to point to the URI of the image I wanted to use so that the main site could show it's own image if it ever needed to.

So I created an icon and referenced in my page like so many examples on the web tell you to:

<link ref="apple-touch-icon" sizes="57x57" href="http://www.somewbesite.com/mysubdomain/apple-touch-icon.png">

However when I tried to add my web page to the Home Screen the icon didn't show and instead iPhone created it's own icon using a screenshot of the page in question.

At first I thought it might just take a little time to kick in but even two months after creation the icon was still the screenshot image and not the icon I had created.

The .PNG file was not corrupt and I tried numerous different locations, images and attribute settings to no avail.

However today I just gave up and placed the image in question into the root of the main site e.g

http://www.somewbesite.com/apple-touch-icon.png

Then low and behold the icon immediately showed up on my Home Screen!

What is the point of the LINK element if you cannot point to locations apart from the root of the site?

Surely Apples own iPhone technology is capable of looking for it's own touch screen image tags?

Am I going crazy or is something amiss?

ISAPI URL Rewriting - Hot Linking

Banning Image Hot Linking

I was updating my ISAPI rules the other day implementing some new rules to identify XSS hacks and new SQL injection fingerprints and I came across some articles on the web about banning image hot linking which I thought was a cool idea. If you have spent time and effort designing images then there is nothing worse than someone just stealing them or even worse hot linking to the image so that your bandwidth is also taken up hosting their images!

I implemented the rules with a redirect to a logging page that logged the referral property to my traffic DB so that I could see which sort of requests were being made for images that didn't originate from the site they belonged to. After a week or so of logging I had enough data to come to the conclusion that I wouldn't be able to implement a hot linking ISAPI rule in the majority of the commercial applications I work on. This is for the simple reason that most sites I develop send out one or more HTML emails to users that themselves make use of hot linking to images and logos e.g using full URLs back to the image on the webserver. Unless I could come up with a rule that could handle every type of webmail or email client then there would always be someone somewhere in the world opening up their latest site generated email, clicking the "load images" button only to get nothing in return.

There are so many different mail clients out there developed in hundreds of countries that no rule could keep up with all the possibilities. From viewing my logging I had at least 2 different Polish mail clients as well as a number of Russian, Chinese and god knows what. So if you are developing a commercial application that has to send out HTML marketing or other forms of email I would advise against it.

However for small or personal sites then there is nothing wrong with implementing a rule to ban hot linkers. One of the cool ideas I read about was to return a banner advert or some other imagery that would annoy the user. However if you are going to use these rules you should know that as soon as the linker finds out you have blocked them they will just download the image from your site and host it themselves if they really wanted it. The original reason for this type of rule from what I have read is to implement it periodically to log those sites who are linking maybe without even blocking the image and then to issue cease and desist orders to the offenders.


The ISAPI Rules for IIS

I have to work with IIS at my current company and we use both 32 bit and 64 bit servers which means we have different versions of the ISAPI DLL installed on each and therefore slightly different syntax. The component I use is ISAPI Rewrite.

You will notice that the rules are slightly different due to the regular expression engine differences between versions.

Both versions do a number of conditional checks to ensure that
-The referer is not blank
-The referer is not the current site which is obviously okay
-The referer is not an image search bot. Looking at the most popular robots.
-The referer is not an email client.
-The user-agent is not a popular search engine bot.
-The image in question must be a gif, jpeg, jpg, png or bmp
-If all those conditions are matched I redirect to a 403 forbidden page.


Version 2.7 ( 32 bit server - httpd.ini)

Notice that I capture the host in the first conditional and then use a back reference to that matched value in the third conditional which ensures only hosts that are not the current site get matched.

RewriteCond Host: (.+)
RewriteCond Referer: .+
RewriteCond Referer: (?!https?://\1.*).*
RewriteCond Referer: (?!https?://(?:images\.|www\.|cc\.)?(cache|mail|live|google|googlebot|yahoo|msn|ask|picsearch|alexa)).*
RewriteCond Referer: (?!https?://.*(webmail|e?mail|live|inbox|outbox|junk|sent)).*
RewriteCond User-Agent: (?!.*(google|yahoo|msn|ask|picsearch|alexa|clush|botw)).*
RewriteRule .*\.(?:gif|jpe?g|png|bmp) /403.aspx [I,O,L]


Version 3 (64 bit server - .htaccess)

RewriteCond %{HTTP_REFERER} ^.+$
RewriteCond %{HTTP_REFERER} ^(?!https?://(?:www\.)?mysite\..*) [NC]
RewriteCond %{HTTP_REFERER} ^(?!https?://(?:images\.|www\.|cc\.)?(cache|mail|live|google|googlebot|yahoo|msn|ask|picsearch|alexa).*) [NC]
RewriteCond %{HTTP_REFERER} ^(?!https?://.*(webmail|e?mail|live|inbox|outbox|junk|sent).*) [NC]
RewriteCond %{HTTP_USER_AGENT} ^(?!.*(google|yahoo|msn|ask|picsearch|alexa|clush|botw).*) [NC]
RewriteRule .*\.(jpe?g|png|gif|bmp) /403.aspx [NC,L]


Quirks and Differences

As always nothing is ever simple especially when you want to implement the same rule across two different versions of an application. As well as the obvious syntax differences with the flags and HTTP header names I found the following:

• Using the IIS converter tool to convert the 2.7 rules to version 3 did not convert all the rules. It could not handle the back references and therefore I explicitly match the site domain in the v3 rules.
• The negative lookahead asserts differ between versions. I could not get them working in 2.7 without putting the trailing .* outside the grouping e.g (?!https?://\1.*).* whereas in v3 they are within the grouping e.g ^(?!https?://(?:www\.)?mysite\..*)
• The documentation recommends NOT using the ^ and $ when using rules with conditions because internally all conditions are combined together to create one rule and this can lead to unexpected behaviour.
• I could not get the Ignore Case flags [I] working in version 2 with the negative lookaheads. As soon as I added the flag the rules would not match. This does not seem to be a problem in version 3 and the equivalent flag [NC] works fine.

Apart from those quirks both sets of rules have been tested on live systems and work fine. However if you are going to use rules such as these you are always going to run into problems with new mail clients or user-agents that come along oh so very frequently and unless you are going to constantly update your ini files you will have a considerable percentage of false positives.

The full ISAPI Rewrite documentation can be found here: http://www.isapirewrite.com/docs/