One of our admins has dropped off her HP system for us to reinstall - no CD's supplied.
There is a HP recovery partition but require the restore CD to access it.
System has a XP Home product key/COA so I installed XP Home using one of our OEM copies here, and then thought Id just change the key to the HP one afterwards.
Cant do it. Everything comes up saying its not a valid key yet when I check on MS's site, it says its a valid key but its for XP Pro, not Home.

I could just disable the activation etc but then she wont be able to update Windows etc.

Any way to get this activated or am I stuck without the HP restore disc ?