(Will Keep Updating)
Some hacks require you to have 4.0, 4.5 Beta or the 4.5 RC Framework so here's the download for it.
.NET Framework 4.0 : Download: Microsoft .NET Framework 4 (Standalone Installer) - Microsoft Download Center - Download Details
.NET Framework 4.5 Beta: Download: .NET Framework 4.5 Beta - Microsoft Download Center - Download Details
.NET Framework 4.5 RC : Download: .NET Framework 4.5 RC - Microsoft Download Center - Download Details
Thank me if I helped /me