This is one of the major pains with using Visual Studio .NET to work with ASP.NET - debugging almost never works on a new install and it can be a major pain to get it working. Noticed this link on Min's blog (he's also on the Debugger Team which helps :-)) - from G. Andrew Duthie - who I always wonder about, what is so bad about the G. bit that it needs eliminating? Oh, and Eric Gunnerson - who I just noticed posted it a bit earlier (and who writes some cracking stuff in his regular MSDN column)