While trying to install Exchange 2013 you receive the error message "A reboot from a previous installation is pending. Please restart the system and rerun setup.
If you receive this error it is a relatively easy fix. Just go to regedit and find the following key and delete it. HKLMSYSTEMCurrentControlSetControlSession ManagerPendingFileRenameOperations
Hit the retry button in setup and it will work.