This article explains how to tackle with "The specified server is not running .NET 1.1" Error and explains the uses of Aspnet_Regiis.exe. After doing a fresh installation of Visual Studio.NET in myWindow XP machine I was trying to open a sample application in ASP.NET.But VS was giving an error. "The specified server is not running .NET 1.1" And the solution : go to C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322 and execute aspnet_regiis -i I got .NET 1.1 installed.. Now everything is working fine.