ReInstall ASP.NET

Try reinstalling ASP.NET on your box using the Administration utility (2.0.50727) to install and uninstall ASP.NET on the local machine.:
Open a command prompt
Stop IIS: iisreset /stop
Change to the .NET Framework 2.0 root directory: C:\winnt\Microsoft.Net\Framework\v2.0.50727Reinstall ASP.NET 2.0 by using the following command: aspnet_regiis -i command.
Start IIS again after it has been run: iisreset /start
Try to access your web page again.