You should be able to tell if it was a legit version or not. It should have a hologram cd...if not it may still be legit (may have lost the original) but at the very least you should have an authentic license key...if you bought a burned copy with the product key scribbled on the cd or on a piece of paper, you know it\'s not the real deal. As for if MS can tell...who knows, but I wouldn\'t tempt it. Either buy it, or use freeware.