Hi, I bought my computer along time ago and it came with windows xp. It had an offer that let me upgrade to windows 7 for free. A year later, I bought windows 8 pro upgrade and installed that. After that, I was upgraded to windows 8.1 pro. Flash forward a bit, I've lost my windows 8 upgrade cd, and since my computer came pre-installed with windows xp/7, I have no discs for those either. My question is, how do I go about reformatting my computer to do a fresh install of windows 8.1? I've used Belarc Advisor to get my Microsoft - Windows 8.1 Professional (x64) key. It gave me two keys xxxxx-xxxxx and then one inside (xxxxx-xxxxx). Can I use these keys to just download the iso of windows 8.1 pro to activate my version of windows? And if so, which key do I use, the one inside or outside of the parenthesis? Thanks for any help.