I made a decision and removed WGA from running on every startup of my Windows, and sitting in Task Manager processes continually for no apparent reason at all.
Thankfully the MS guide helped me remove it
Yes it re-installs if I ever go to MS Servers and decide to download certain things, including manual MS updates (Note automatic MS Updates do not require WGA)
I then uninstall WGA again, as I don't like any process consistently running in the background, on every Windows startup, for no other reason
Registry editing does come with warnings and should not be "played" with, unless you don't mind things not working again
Simple registry editing from a non-experienced user, even if they create backups of original keys, can cause Windows not to start again even in Safe Mode.
Therefore "backing up" registry keys won't help all the time (even most of the time)
I advise you not to play with the registry (as I have advised users on every forum I have been on)