Prepare for a long winded post.... I am in the midst of upgrading my PC CPU and MoBo. All new mobos require windows 10. I have a windows 7 64 bit CD and heard you can upgrade to windows 10 for free. I am trying to do that but the Windows 10 upgrade keeps failing because I think it may think I have an illegitimate liscence since I used that cd to install windows on 2 computers. After I installed it on my desktop however many years ago I thought I'd get my dead laptop back up and running. I installed windows on my laptop only to have the HDD die on me again a few weeks later. So that laptop is now locked away in the basement where it has been for years. I am learning now that my windows liscense was only good to install on one pc, why I was able to install it on both without issue is beyond me. So am I hooped now because I installed windows on that 2nd computer? Having to purchase windows 10 for 150$ is really putting my upgrade over budget. Could I reinstall windows 7 from the cd on my desktop to relegitimize it? Any help is greatly appreciated.