OEM stands for Original Equipment Manufacture. When software companies such as Microsoft distribute OEM software for sale it is only to companies and individuals who are registered with them as system builders. OEM software by definition is only for the system builders to install on a brand new computer for retail sale to an individual called an end user.

An end user is someone who is buying the computer and ultimately will operate the system for their own use. When the OEM software is installed correctly, the end user will take the computer out of the box.At start up the user sees a screen to register the software then set up any other equipment attached to the system such as printers, monitors, scanners, etc..

What is the difference between OEM and retail versions of software?

Other than the price and the packaging, there is little difference between the two. OEM software is sold at the lower price without the box packaging because it is sold in sets of 3 or cases of 20 cds. The OEM software is sold only through wholesale distributors that are supposed to check that the individual or business purchasing the software is in fact a legitimate business with a state tax ID. Also OEM software MUST be sold with an item of hardware such as a hard disk drive, cd-rom drive, video card, etc.. Also, this software may not be transferred to another machine once installed.

So is it legal to purchase OEM software on EBay?

Buyers may purchase the software providing that the seller is also selling the software with a hardware item. A careful buyer should make sure when checking the listing that there is a hardware item included in the sale. Also, find out what the item is exactly. It would be too easy to say as a seller " I am selling this OEM software with a hardware item" but not say exactly what that item is. When the software is shipped, again, the seller might not include the mystery "hardware item" since he never specified what that item is.

How can I tell if my OEM software is legit?

On the cd is a hologram of the Microsoft XP logo. If you are unsure of what the logo should look like, go to Microsoft's website and compare the logo. Also there should be a sticker on a piece of paper that says "Microsoft (insert software name here)Certificate of Authenticity" with the cd. This is you product key that will need to use the software after installation.

What if the OEM software I bought is not legit?

First, confirm with Microsoft that the software is indeed bogus first. You can find the contact numbers for Microsoft for this on their website. Next, after confirming that the software is phony, contact EBay with the auction information and who you bought the software from. If you used Pay Pal, check with them to see  if your purchase was covered under the returns policy.

In conclusion, the best way not to get burned buying bogus, or illegal software is to use a reputable vendor. Remember, you get what you pay for. If you went to save a few bucks and bought something illegal, the rule is "let the buyer beware"!