Microsoft .NET Framework v3.5

Source
problem installing Microsoft .NET Framework v3.5 on Vista
the fix: 

Control Panel --- Programs and Features --- Turn Windows features on and off --- Microsoft .NET Framework v3.0 and select all of the following check boxes:

•  Windows Communication Foundation HTTP Activation
• Windows Communication Foundation Non-HTTP Activation
• XPS Viewer

http://codekeep.net/ASPNET/code/snippets/16827/Unable-to-install-NET-Framework-30-35-VS2008-Solution/view.aspx