I was trying to install Exchange Server 2007 SP3 Management Tools on a Windows 7 PC. During the installation I expected the following error:

A reboot from a previous installation is pending. Delight restart the system and rerun setup.

I resolved this error by deleting the the REG_MULTI_SZ value PendingFileRenameOperations from HKLM\SYSTEM\CurrentControlSet\Control\Session Administrator\PendingFileRenameOperations

Check it out:Clint Boessen’s Blog