A recent install resulted in the following error:
“Setup is unable to proceed due to the following error(s): A system restart from a previous installation is pending.”

The problem was related to a registry key “PendingFileRenameOperations” located at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager.

Fix
Rename the key to PendingFileRenameOperations1 and you will be able to proceed with the install.