PROBLEM OF RUNNING ASP.NET APPLICATIONS ON WINDOWS XP SERVICE PACK2

You can also try repairing your IIS mappings. I have
occasionally had
this cause problems.

Go to the command prompt

Type the following:

<Windows folder>Microsoft.NETFramework<Version
Number>aspnet_regiis.exe -i

You will need to put in your relevant information for
Windows folder
and ASP.Net framework version number.