I'm thinking about putting my laptop back.
When I bought Windows 8, I got a free update to Windows 10. How is that when I reset my PC? Can I still upgrade to Win10 for free, or do I have to pay for it?
You swapped your Windows 8 key for a Windows 10 key.
Say you only have Windows 10
It is best if you do not reset the PC, but completely reinstall Windows.