I have three versions of .NET framework installed.
Microsoft .NET Framework (English) v1.0.3075 -- Size not listed
Microsoft .NET Framework 1.1 -- 35.11 MB
Microsoft .NET Framework 2.0 -- 88.36 MB
Also,
Microsoft Application Compatibility Toolkit 5.0 -- 30.01 MB
I remember there was some utility (might be the dll) that required .net version 1.1 so I had to find it and got it installed as well as v2.0.
Hope that helps.
EDIT: I'm not using SLI. Only have a single 8800 GTX.