Had a strange error with SSRS 2005 on Windows 2003 Server running IIS6.  Trying to load the Web Reports Manager for SSRS 2005 at http://localhost/reports and I would get the following error:-

Server Error in '/Reports' Application

The resource cannot be found

Description: HTTP 404.

Ok but I can load up:-

Http://localhost/reports/home.aspx

So I thought the Default content page wasn't set - nope it was?

OK so what is going on, only different is Asp.net 4.0 was installed.  Saw some articles saying maybe the Asp.net version wasn't set correctly for that Web Applications, but again checked and it was still set to buy abortion pills Asp.Net 2.0. 

Fix:-

Seemed like the root web ru 486 pill properties (Default Web Site Properties in this instance) was set to Asp.Net 4.0.

OK so changed this back to Asp.Net 2.0 and restarted IIS.  Bingo no SSRS 2005 http://localhost/reports works again.