I am running multiple wordpress blogs on the following setup: Server 2008 R2; IIS 7.5; PHP 5.3.3; MySQL 5.0.7; I upgraded my wordpress install from 2.9.2 to 3.0.2 (on 2 different sites) today and the upgrade went fine. I can serve .php pages without errors, log into the admin system etc. I can browse my blog by going directly to mywebsite.com/index.php, but when I try to go to mywebsite.com (without the index.php) I get he below 500 error. I reset IIS, removed and re-attached the default document, but I am running out of ideas. Please if anyone has a solution for this that would be great. This is the 500 error I am getting: Error Summary HTTP Error 500.0 - Internal Server Error The page cannot be displayed because an internal server error has occurred. Detailed Error Information Module FastCgiModule Notification ExecuteRequestHandler Handler PHP FastCGI Error Code 0x00000000 Requested URL http://mywebsite.com:80/index.php Physical Path D:\mywebsite.com\index.php Logon Method Anonymous Logon User Anonymous Thanks Stephan