"WindowsUpdate_80070570" "WindowsUpdate_80073712" Errors

Fixed the above stated problem for me. EDIT: It also fixed a problem where the Service Pack couldn't be installed!

net stop wuauserv

net stop bits

net stop cryptsvc

ren %systemroot%\System32\Catroot2 Catroot2.old

net start cryptsvc

ren %systemroot%\SoftwareDistribution SoftwareDistribution.old

regsvr32 wuapi.dll

regsvr32 wuaueng.dll

regsvr32 wucltux.dll

regsvr32 wups2.dll

regsvr32 wups.dll

regsvr32 wuwebv.dll

net start bits

net start wuauserv

net start Eventlog

exit

Reboot and try update again.

SOURCE: http://answers.microsoft.com/en-us/windows/forum/windows_other-windows_update/windowsupdate80070570-windowsupdate80073712-errors/8a1ff2d4-0c96-495c-b22a-759f9b66f2e6