Today I have downloaded and installed a new Windows Update for my new Windows 7 computer.
The Windows Update download was pointing to Knowledge Base article KB974431 where the update is said to be a release to improve the stability and reliability of Windows 7 and Windows Server 2008 R2.
You can find more details on the Windows Update KB974431 at Microsoft Support
The download size for the Windows 7 update installation file is about 20.6 MB
Please note that the Windows Update installed KB 974431 Windows 7 update requires a computer restart. You should have to reboot your Windows 7 computer or Windows Server 2008 R2 server after the Windows 7 fix is applied.