You should open up IE on the server for which you are looking for this info, and go to this site: http://www.hanselman.com/smallestdotnet/
That’s all it takes.
The site has a script that looks your browser’s “UserAgent” and figures out what version (if any) of the .NET Framework you have (or don’t have) installed, and displays it automatically (then calculates the total size if you chose to download the .NET Framework).