I am planning to sell several Dell Dimension 8200 and 4600 computers with XP Pro COA labels attached to them. Should I just leave the COA labels on the computers and reformat their drives? Can I take off the COAs and reuse them on new computers? I am unfamiliar with the correct process when it comes to reselling computers but I would prefer to be able to reuse the XP installations since I paid for them. Thanks.