Can I sell a computer with the same Windows 10 key that I used in my personal machine?

Question

Somehow I activated Windows 10 with the same key that I used 3 years ago on my own PC. This computer that I plan to sell had a missing hard drive so i had to start fresh with a new drive. I couldn't reset or use the OEM key (windows 7). 
I read somewhere that win10 keys have something to do with Microsoft accounts, so i'm just asking if I could sell it as is, or if the next user will run into activation issues once they sign into their own Microsoft account or use it on the internet for some time.
Thanks

Answer 1

The OEM key follows the machine irrespective of who’s Microsoft account is logged in, otherwise what do you think would happen if there were several accounts on one computer each with there own Microsoft login?

If you have managed to activate the same key on two machines  eventually this will be detected and flagged and on or both machines will be deactivated.

Normally OEM windows 7 keys are accepted as a valid key and converted to a windows 10 digital license, again, this is on a per machine basis and cannot be transferred

Answer 2

If you put the same copy of Windows 10 on two computers eventually both computers are going to become deactivated. The proper way to do this is can you use a copy of Windows 10 which matches your Windows 7 key that is on the side of the computer for instance if it says home premium you have to use Windows 10 home premium if it says professional you have to use the professional a Windows 7 home premium key will not activate a Windows 10 professional a Windows professional key will not activate a home premium. But if you make a Windows 10 installer using the Windows 10 media installation tool and you choose the correct install to go with the Windows 7 key that you have it will positively activate. If it's not activating it's because somebody has used the key on too many computers.

Answer 3

Start Menu > Type 'Activation Settings'. 

Answer 4

Sell the computer without Windows 10 installed.   Install UBUNTU Linux (it is free).

Let the new owner worry about Windows 10 if he wants it.