You must use the Role Management Tool to install or configure Microsoft .NET Framework 3.5.

When you are trying to install Visual Studio 2008 professional edition on a Windows 2008 R2 suddenly you will be prompted to an error saying "You must use the Role Management Tool to install or configure Microsoft .NET Framework 3.5."

In this case what you have to do is, from the Service Manager install the .NET Framework 3.5.1 Feature as Windows 2008 R2 is integrated with .NET Framework 3.5.


so before installing VS 2008 make sure that you are enabling this feature .NET Framework 3.5.1 Features via the Add Features Wizard in Server Manager.