Exchange 2010 Error: A reboot from a previous installation is pending.

If you are seeing this error while trying to apply an Exchange SP or RU and you have restarted here's a quick fix for it:

**MAKE SURE YOU RESTART FIRST JUST TO MAKE SURE IT IS NOT CLEARING**

Delete the  below key from the registry:
 HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\PendingFileRenameOperations

After this you will be able to continue your service pack install.

Good luck.