Solutions: Visual Studio.NET 2003 Debugging Errors

• Run the aspnet_regiis.exe via the Visual Studio.NET 2003 Command Prompt ( - Start Menu > Microsoft Visual Studio.NET 2003 > Visual Studio.NET Tools > Visual Studio 2003 Command Prompt - ) to register asp.net into IIS. The aspnet_regiis.exe is availabe in C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322. This scenario should be applied when you re-install either IIS or Visual Studio.NET 2003

• Also check the <processModel> tag of your machine.config, check the value of <userName> attribute. It could be machine, if so change it to system. Finally restart IIS and retry. Source: http://www.experts-exchange.com/Programming/Languages/.NET/ASP.NET/Q_21547213.html

Further Reference:
http://msdn.microsoft.com/en-us/library/h35f56yz(VS.71).aspx
http://msdn.microsoft.com/en-us/library/dwesw3ee(VS.71).aspx