Have to agree with TechMail here, this looks like a hot one, and you are in receipt of stolen property.
2003 is not a domestic OS, your best bet is to contact the police asap, you should be safe from prosecution if you do that immediately, ie soon as you become suspicious, as the authorities want to encourage the reporting of such crimes.
If it is what I think it is, it will be part of a lot of equipment being sold on, and they will want to crack the "ring" stealing such things.
Who knows, you may even get a reward for evidence leading to the successful prosecution of the criminals. it's probably a company that lost a lot of equipment, they will want to both catch this ring and get any equipment back, mainly because there may be a lot of irreplacable data.
They should be very, very grateful.