Some of you hit the 0xC000009A exit code when installing Service Pack 1 for Windows 7/2008 R2 on systems where multiple language packs have been installed.  This issue has now been resolved and is published here: http://support.microsoft.com/kb/2534366

Note, this fix must be installed on multi-langpacks system BEFORE installing Service Pack 1 to ensure that the multitude of servicing operations generated on these types of installations doesnt fail the service pack install.

--Joseph