VS2010 error: Unable to start debugging on the web server

I run the following command in run window for installing .net 4 framework.

Now its working fine...

C:\Windows\Microsoft.NET{FrameworkFolder}\v{FrameworkNumber}\aspnet_regiis -i   

Reference link  http://stackoverflow.com/questions/2878136/vs2010-error-unable-to-start-debugging-on-the-web-server