Smannesman: Just did the Windows 10 upgrade, to activate the free copy..
now I'm wondering if I should do a completely clean re-install of Windows 7 and Linux (Mint) tomorrow... Must be the season! I just did exactly this. Though in hindsight I'm not sure I did a "complete clean reinstall" of Win 7. I put in the discs I made (OEM) when I first got this computer. It did a (very quick!) format, and reinstalled Windows but it looked more like via OEM than a Windows ISO. And I was never prompted to do some of the "first start" stuff that I thought I remembered doing (I did have to make a User Account and select time zone, I didn't need to activate Windows and I didn't make some of the network / IPv6 choices I thought I remembered making a few years ago).
I'm still (lazy) working on copy pasting a couple files I backed up but I have all my updating done, sans game installs (this desktop is mostly my game / browsing / "messing about" computer). I even did some partition stuff - I think I did it in a bit less than ideal manner if I want to make more but I should be okay.