OK, Check this out! I bought a hp-530 notebook from a retailer and had them install the xp pro downgrade, It did not come with os recovery disk so I ordered them from hp in case I ever needed them and now I find myself in need of reformatting c drive. When I do try to install os cd I get error message: D:\i386\WINNTUGP\NETUPGRD.DLL file is missing, I then close error message and the enter product key window pops up, I then enter my product key and it says my key in not valid, after this I manually extracted the D:\i386\WINNTUGP\NETUPGRD.DLL file from the cd and placed it in the hp program files folder, still can't install xp. The online chat rep summed it up to a corrupt os cd. Please Help!
Ok, I assume the Windows XP they installed for you is not a corporate edition (it's rarely the other case), meaning that the cd key can only be used once (when you asked them for the xp pro installation and they did it). If that is the case, you need to buy a key by either purchasing a new Windows disc or just getting a new key through Microsoft.