Microsoft XP Home re-activation?

[Belial The Mad Hatter]

Ok, So I have been using Microsoft Windows XP Home Edition on the same
computer for about two years now.
My computer had been giving me all types of hardware problems due to an
overused mother board.
I recently purchased a Windows game, Namely Assassins creed.
Being one who never checks system requirements I came to find out that my
processor was not good enough.
After purchasing a new processor and mother board (to fix all my hardware
problems) now Windows wants me to re-activate.
I assumed this no problem. It still showed all my personal desktop settings
and sent me to a step by step activation process.
Because it would not let me do anything yet I was unable to connect my
internet so I had no choice but to use the phone activation.
There I was aided by a helpful computer.
The computer asked for my installation ID.
After I had given the computer this code I was informed that some how my
Windows XP was installed with the wrong installation ID...?
I was wondering if this was a common problem or if there was a fix for it.
I would really like the opportunity to play my game and to access my files.
Could someone please help?

 

[Anteaus]

If this is an OEM version, the ID it was installed with may not match the one
on the license sticker. The one on the sticker should in principle work. You
need to select phone activation, then 'enter a new key' and put this in.

Though, I have known OEM stickers to have invalid numbers. I guess the OEMs
don't bother to check the numbers properly since the machines are
pre-activated anyway.