This Blogging Platform is built on WordPress MU, WordPress MU is slightly different to WordPress in that it has support for multiple independent blogs on top of a single user database, when running in folder per blog mode WordPress MU is totally dependent on the apache MOD-ReWrite feature to rebuild URL in the fly. This is a feature that has been missing from IIS until now, Microsoft have released, albeit CTP1 at the moment, a URL rewrite module for IIS7.

WordPress and WordPress MU can also use url-rewrite to create “friendly” permalinks

Well I did it, installed a copy of WordPress MU on IIS7 in folder per blog mode

• Server 2008 enterprise
• IIS7 URL-ReWrite CTP1
•  WordPress MU 1.5.1
•  mysql-5.1.25-rc-win32
•  ZendCore-2.5.0-Windows-x86

Using the URL-Write Module and some help from IIS.net, it was fairly straight forward; URL-ReWrite is still in CTP1 and has a few known issues. For instance the import wizard correctly identifies the  [L] parameter in .htaccess and create the correct XML, but the ”stopProcessing” attribute does not get copied to the web.config file and the ReWritecondition flag created a NEW rule with no action , rather than apply the condition to the next rule.

So after a bit of fiddling and some help from IIS.NET I got it all working including CSS and themes for folder based blogs.
The Only issue I did not fix was an issue with ONE of the CSS files which controls the layout of the TOP of the admin pages,

SORTED !!!!!!!!!!

Just so i dont lose it the web.config file is here

And dont forget the rewrite server variable fix too

This make an intersting read

HOW TO: wordpress on IIS7 with some extras too

http://mvolo.com/blogs/serverside/archive/2007/08/12/IIS-Authentication-plugin-for-the-WordPress-PHP-blogging-engine.aspx