Ok so i got a laptop from a customer that had XP Pro on it. It had a really bad virus so it needs formatting. There was no sticker for the serial key for Pro but i got it off there before i formatted. Will that key not work if i use an XP Pro SP2 install disk and it was made for XP Pro pre SP2? It also has a home sticker on the bottom, but again, dose it matter on the service pack?