F8 when your computer boots and chose "Repair your computer"
Set the keyboard layout and login with your administrator password
Choose Command Prompt from the menu
Type: C: and hit enter
Type: notepad.exe c:\windows\winsxs\pending.xml
Find _0000000000000000.cdf-ms
(thats 16 zeros) and remove the following text and save the file
More recovery options here:
http://windows.microsoft.com/en-US/windows7/What-are-the-system-recovery-options-in-Windows-7
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