Bought XP OEM a few years ago. Hard drive needed to be wiped. Discovered that I lost Prod ID in move. Don't want to spend $199.00 for another copy. Any help would be appreciated.

Sounds like you are out of luck. If you still had the OS installed you could get it out of the registry.
You can get
Vista Home premium for $99
Vista Ultimate OEM for $179 (which I would only recommend over home premium for it's simple built in back up, which you could do cheaper with third party software)
XP Pro OEM for $139
Newegg.com - Operating Systems, Microsoft Windows Vista, Windows Vista 32, Microsoft Windows XP, Microsoft Windows Media Center, Linux

When you get the new OS installed, find a back up solution that works for you. It's not if you'll lose data, but when.

Did you actually wipe the drive or just reformat it?

If you just reformatted there are some recovery programs that can actually retrieve the data well enough for you to search for and find your lost license key.

Just curios...why you didn't attach the COA certificate to the computer you bought the OEM operating system for...as per agreement when you installed the operating system. Had you followed procedures then there would not be this issue going on now...would it!

If you indeed bought a OEM machine, then life can be easy: the product code probably is written on the cover over your PC. That one works provided the configuration of your PC is identical compared to the one you bought.

Thanks for the reply. Got it handled.