Prova a

Microsoft .NET Framework Repair Tool >

http://www.microsoft.com/en-us/downl....aspx?id=30135

Se la devi disinstallare disinstallala con >

.NET Framework Cleanup Tool

http://blogs.msdn.com/b/astebner/arc...8/8904493.aspx

e scaricalo da

http://www.microsoft.com/it-it/downl....aspx?id=17718