Dear Seun T
Coming from an elder sis

. the only option you may have is to reinstall you windows even though its that unoriginal one you have. then turn off your automatic updates, because I guess that message started popping up the moment you tried to update your version of windows (which in this case is not original).
I just saved my system from the same thing. My system is partitioned so, I installed the new windows xp, on my 2nd drive, while i figure out how to remove the former one
Hola