Microsoft KB 947821 (http://support.microsoft.com/kb/947821)

If you’ve gotten one of those cryptic 0x800xxxxxx Windows Update errors, Microsoft finally has a fix for Vista and higher, no XP solution.

Fix Windows Update corruption errors such as 0×80070002 and 0×80070057

Windows Update corruption errors prevent Windows updates and service packs from installing. For example, an update might not install if a system file is damaged. If the error you see is in the following list, try the solution in this article.

0×80070002 | 0x8007000D | 0x800F081F | 0×80073712 | 0x800736CC | 0x800705B9 | 0×80070246 | 0x8007370D | 0x8007370B | 0x8007370A | 0×80070057 | 0x800B0100 | 0×80092003 | 0x800B0101 | 0x8007371B | 0×80070490

Windows 8.x and Server 2012 Rx

To resolve this problem, use the inbox Deployment Image Servicing and Management (DISM) tool. Then, install the Windows update or service pack again.

1. Open an elevated command prompt. To do this, swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search. Type Command Prompt in the Search box, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
2. Type the following commands. Press Enter after each command.
   Note It may take several minutes for each command operation to be completed.
   • DISM.exe /Online /Cleanup-image /Scanhealth
   • DISM.exe /Online /Cleanup-image /Restorehealth
3. Close the command prompt, and then run Windows Update again.

DISM creates a log file (%windir%/Logs/CBS/CBS.log) that captures any issues that the tool found or fixed. %windir% is the folder in which Windows is installed. For example, the %windir% folder is C:\Windows.

Windows 7, Windows Vista, Windows Server 2008 R2 or Windows Server 2008

See the KB link for the download you need. http://support.microsoft.com/kb/947821