I installed a copy of Windows XP media center 2005 as a test drive on my PC, without activating it. The allowed period lasts for 60 days. Unfortunately I was ubsent for a long time and the allowed period without activation expired. So whenever I try to login I get the activation prompt and I can not go any further. The question is, can I purchace my own copy of windows media center edition 2005, and use the info from the new one to activate my already installed operating system? I don't want to proceed activating the product using the original product key for several reasons including: someone else bought it, is not valid, uncertain what will happen if the key is not valid (I don't want to lock up the system for ever), etc. Please advise. Formating is not an option, I need to access the PC and continue using it as is.