Installed Windows 8 Upgrade AFTER Formatting HD - any way to activate?

I had an XP system - formatted the HD then ran Windows 8 Upgrade install. Install was fine.

It cannot activate and gives me the 'this is an upgrade' error. Is there ANY way to fix this (MS Support call or something?) before I scrap the entire Windows 8 install, Reinstall XP, then upgrade to Windows 8 the proper way?

I hate to waste the day's worth of config-the-new-os time if not absolutely necessary.

Error was the 0XC004F061 from Windows 8.