There're 5 downloads available via Microsoft Download Center, and just as many offered through TechNet, after users register with the website.
- WUSignUpTool_x86.exe tool enables 32-bit Win7 PC to participate in the public beta via WU. Run this tool and then check for updates in Windows Update.
- WUSignUpTool_x64.exe tool enables 64-bit Win7 or Windows Server 2008 R2 PC to participate in the public beta via Windows Update. Run this tool and then check for updates in WU.
- windows6.1-KB976932-X86.exe app installs the public beta to a 32-bit machine running Win7.
- windows6.1-KB976932-X64.exe app installs the public beta to a 64-bit machine running Win7 or Windows Server 2008 R2.
- Finally, 7601.17105.100929-1730_Update_Sp_Wave1-B1SP1.0_DVD.iso disk image contains the standalone update packages for the public release candidate.
Windows 7 and Windows Server 2008 R2 SP1 RC is time-bombed and set to expire on November 30, 2011.