I have just installed WordPress 2.6.5 on a Windows Server 2003 box, IIS6, PHP 5.2.6, and MySql Server 5.0.
The install went well although my pages now render improperly, seemingly not using the style sheets.
Thinking this may be the result of a corrupted file somewhere, I downloaded a fresh version of WordPress, unzipped it into a new directory, pointed IIS to the new directory, created a new database, and re-installed.
Please do not suggest I abandon IIS 6 for Apache. I really need this to work on an IIS server.