Windows 7 Service Pack 1 has been in development for quite some time now and Microsoft has released the beta version of SP1 back in July. Today, Windows 7 SP1 Release candidate (RC) is available for download. Windows 7 and Windows Server 2008 R2 SP1 Release Candidate includes previous updates delivered over Windows Update as well as continuing incremental updates to the Windows 7 and Windows Server 2008 R2 platforms.
In order to download and install the Windows 7 and Windows Server 2008 R2 SP1 Release Candidate you must currently have a Release to Manufacturing (RTM) version of Windows 7 or Windows Server 2008 R2 already installed.
If you have previously installed the Windows 7 and Windows Server 2008 R2 SP1 Beta on your machine, you must uninstall the beta before installing the Release Candidate.
The 64 bit version has 865.4MB download size while the 32 bit has 514.7MB.