Windows 10: Upgrade from windows 8 to windows 10 on laptop

I think I will be getting a laptop that has windows 8.. I would like to upgrade it to windows 10. (I have a windows 10 desktop)

1st.. is that still possible to do.
2nd.. should I do it with the orginal owner or after changing it to my own credentials..
3rd .. where would I find the key.. or is it needed.
4th ... and most important.. Please add any information that I will, (or might) need to know before doing this..

Thank You
I Do Not at this time have the laptop or version number at this time.. It probably will be a couple weeks before the current owner gets their new replacement laptop.

:)

 

Unlocked Realtek HD Audio Drivers Windows 7 & 8 (With Dolby Digital Live and DTS Interactive)

DTS supported natively by Windows 8/8.1 and it should work on windows 10 too just DDL require to unlock your driver .

 

How to reinstall Windows 10 if my computers used the free upgrade from 7 and 8?

Will windows 10 still accept the license keys from 7 and 8 now if I reinstall my computer?

Does Microsoft keep a list of users who upgraded to Win 10 using their 7 and 8 keys so that when users need to reinstall windows 10 the old keys would work?

Do I need to call in Microsoft to ask them to activate my Windows 10 when I give them my win 7 keys?

Both computers are laptops. The windows 7 machine had the serial printed on the back, and I needed to enter that when I upgraded to 10. The windows 8 machine had the serial built in inside its boot system so I didn't need to enter the key when I upgraded to 10, but I did manage to write down the keys using a fetcher program.

 

Windows 10

no, you can't go back..
I suggest creating a backup image of your os drive