My in-laws bought a used PC that came with XP Professional. After getting a nasty virus, they re-installed Windows, but used a Home Edition disc that came with another computer they have.
They were, of course, unable to activate the new copy of Windows, since the license key was for the Professional edition. They don't have any Pro discs, and they can't use the license key that goes with the disc they used to re-install with, since it's in use on the other computer.
So what's the best option at this point? Find a download of an XP Pro disc somehow? Will it have to be an OEM Pro disc? (since the computer was most likely OEM and not retail)