hi hope yall can help me to understand this. i have many computers i buy a sales , mostly i buy dells but there are other brands,my question is ,are the cd keys on the side of the computer the same as the two boxes i bought from staples? i have windows home upgrade and windows pro ,ive googled this many times,,what i do on these computers is wipes hard drive reload the matching windows back on that machine but it want let me change the cd key to the cd key on the side of the computer. need help understanding this ,please thanks