Windows Media Player and WGA

I formatted and reloaded WinXP Home SP2 in a PC about a month and a half ago. It activated OK and I did the updates w/o incident. A few days ago, the PC's owner was trying to watch something or listen to something and was told to update Windows Media Player (probably just needed a codec) so he installed WMP11. But now WMP won't launch because it says that the OS isn't genuine and may be counterfeit. I used his CD and product key (the CD is a copy and I used a keyfinder for the product key before formatting). If it activated and installed the updates, why is it now saying it's not genuine? I thought activation and update installation checked that.... Could WGA be wrong? If it is wrong, how do I know? and what do I do to get everything right? I'm not trying to circumvent any laws; I'm not trying to pirate anything; I want to make this right. If it activated, it should be genuine, right?
Thanx in advance for any help, ideas, suggestions....

hd2k

Is there a way to check the product key? Like a web site or 800 number where I provide the product key and I'm told if it's legit or not:confused

 

Sorry, but the first few updates always go o.k.
Then at some stage it gives you the wga in an update, and then if it fails it, you see this.
Unfortunately wga is'nt perfect, and will do this , now, and again.- I have seen it.
Do a system restore to before the wga failure and try updating again, sometimes that works

 

If you telephone the microsoft offices, and wait for a real person to answer, its the only way to check it out, that I know of.

 

Yeah- that's how I activated 6 weeks ago. Anyway, problem solved. I uninstalled WMP11, installed a codec pack, and tried the guy's CD on WMP10 (or WMP9; whatever the XP default player is) and it worked fine. So now I just have to call M$ and find out what's up with the key.... thanx.