I went ahead and, replaced the 'spinner' HD with a SSD in my homebrew desktop earlier this week; (tried) to reload my (legit) Windows 7 and Key Code, popup told me said code is invalid. Tried to get onto MS Support and, they basically said there was nothing that could be done. I was able to extract my data and OS from the dying spinner and, get it onto its replacement, using a third party software, that was recommended to me in a Facebook group. Now; does the above mean I need to 'bite the bullet' and, go with Windows 10 and, if such the case, which variety of Win 10 do I purchase? Note this is a personal PC at home.