My install of Win10 took a crap on me and I need to reinstall. Trick is, my install of 10 was a free upgrade when MS was handing them out for Win 7 users.
I have my Win 7 disk to install, but how do I upgrade to Win10 now?
Two options:
1. Do a reset (the Windows 10 "CD" is built into the OS now)
2. Download the USB installer (or burn a DVD)
When you install Windows 10, it registers your unique hardware ID to Microsoft's online database. Any time you re-install Windows 10 on that machine in the future, you can simply skip the license key entry & once you get online, it will activate itself automatically. As far as the reset goes, this is the basic procedure:
Settings > Update & Security > Recovery (tab on left) > Reset this PC ("Get started" button) > Remove Everything > Remove files and clean the drive
This will wipe everything off the drive & re-install a fresh copy of Windows 10. Alternatively, you can either burn a DVD disc or a USB install disc, but you really only need to do that if your Windows 10 install is completely borked or if you have a blank boot drive that you want to swap in. If, for whatever reason, you'd rather use your Windows 7 disc to install, you can still install the Windows 10 upgrade from here:
https://www.microsoft.com/en-us/accessibility/windows10upgrade