See if this works:
1. Open the start menu.
2. Type “cmd” into the search and right click on “cmd.exe” and choose “Run as Administrator”
3. Type in “takeown /f C:\Windows\winsxs\pending.xml”
4. Type in “cacls C:\Windows\winsxs\pending.xml /G < USERNAME >:F” Note: Your user name will display when you execute step three. (Don’t enter the “< " or ">“)
5. Type in “del C:\Windows\winsxs\pending.xml”
6. Reboot
7. Downloaded & install the Windows update Agent.
32-bit Users Download it Here:
http://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x86.exe
64-bit Users Get it Here:
http://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x64.exe
8. Start Windows update