Not sure how microsoft will handle this and I intend to ring them tomorrow. The spare pc is a Dell machine which came with the traditional green legitimate xp disk. I also once had the pc looked at by a local reputable pc shop for a virus and spyware problem. I also had to provide them with the accompanying xp license code for a reinstall. Anyhow-the same pc became infected again and I did the reformat etc myself. When I installed the operating system,the accompanying license details were rejected. I do not understand this as they had been previously accepted before. Does anybody know if Microsoft will issue me with a serial that works this time as I am a bit concerned that the computer shop may have continued to use the serial without permission? Some Indian bloke at Microsoft gave me another number to ring on Monday.