Windows Mystery! Key wont Work? Not same version as installed!

[spinstorm]

I have a mystery for you guys, I would appreciate any idea what MS would say about this.

My friend has a HP Laptop which has an official COA on the bottom for XP Home but the version on the laptop is XP Pro!

Whats even stranger is I am unable to change the serial to the number on the bottom as it says it is not correct!

Apparently she bought it used from some one - and maybe he put a pirated version on XP Pro on it - but that doesn't explain why it wont accept the XP Home key on the bottom! Whats going on? and what would MS say if I called them...?

So far (and I am not quite sure how) there is no WGA warnings coming up but it obviously does not want to work on windows update!

 

[spinstorm]

You say that but I had an old PC which was not a genuine copy of windows and which was XP Home - and I changed the key to XP Pro and now it says XP Pro on the system details!

So unless MS produced XP like they have Vista where you can simply change the key/upgrade then something strange is happening there as well!