I recently installed windows 7, visual studio 2008, and .net framework 3.5.
With these installed, I was unable to find the .net framework configuration tool.
It
It is included in .NET 2.0 SDK. You need to install the SDK to get it.
ADDITION: Here is a separate link for the .NET 2.0 SDK (64 bit version) for use on 64-bit machines.