When I update DVDFab it usually says to reboot when installing.
But is the reboot just needed for new / first-time installs or does it always really need a reboot for updates?
Every so often there is a installation of DVDFab where you are asked to reboot I wouldn't worry about it, mainly it's when there is a major update or one with many changes.
What actually requires a reboot in any program you install is certain files are being used by Windows . These files can't be changed or replaced while in use. The reboot allows the change to be made before Windows is actually started or while starting before the file that was in use is in use again.