IIS 5 Isolation mode
A couple of weeks ago I had some trouble with windows 2003/IIS 6. Finally I got my asp.net application which uses a COM component to work under windows 2003. I tried everything, I even gave my Network Service account administrator rights and even that didn't work. Until I found the IIS 5 Isolation mode option in the IIS manager. So if you're having problems getting a asp.net application to work under IIS 6 and getting desperate, try the IIS 5 Isolation mode. You can find it this way: Right click on Websites in the IIS Manager, choose Service and check the IIS 5 Isolation mode checkbox.
From: Jonne Kats
Via: Tech Guru