If I do a complete reset of my Windows 8.1 computer will it reinstall the last/latest windows 8.1 OS or will it rest to factory operating system which was W 8.0? Or, if I update this current 8.1 to windows 10, then do a complete reset, will it reinstall to the last OS (Windows 10) or will it reinstall the factory provided 8.0?
Reason I'm asking is I've been using this computer on 8.0/8.1 for over 7 years and its getting slow. I have a new W10 desktop on order and want to use this old laptop as a spare and back up.
And, I don't want to be stuck with an old 8.0 OS.

By ‘reset’, do you mean a utility provided by the manufacturer of the laptop?

If it's recovering from a set of disks or from a recovery partition, it'll be whatever came with the computer (8.0). If you're installing from scratch, it'll be whatever version you're installing.

I’m assuming the same as Simon, unless you are talking about some third-party backup program that creates what they call a reset disc.

I realize this is a backup machine, but if it were mine I would just install Windows 10. That should clean up some sluggishness. And you’re not kicking the can down the road to when you can’t support Windows 8.

FYI - When I upgraded from Win 7 to Win 10 I did not lose any programs or data. I would assume, I know assuming is dangerous, that would also hold true for Win 8.1 to Win 10.

You should be able to install Windows 10 directly over the top of Windows 8 and etain all of your existing programs.

My opinion on the upgrade path? Leave Windows 8 behind in the dust. Update to Windows 10.

I agree. Leave 8 in the bin with XP, Vista, and 7 where they belong. As a Mac user, Windows 10 is the first one where I've said "oh hey, this one's not bad".

Thanks for your replies. I’ve been absent a few days. The process is; W8.0 is factory install. Updated to 8.1. I don’t care to keep any old programs or files be cause I’ve backed up only the programs and files I want onto an external thumb drive (which does not contain all the excess that I don’t want).
The reset procedure is part of Windows in Settings-Recovery-Reset. It says it will remove all programs and files and reinstall Windows. So, with that info, do you think it will reinstall 8.0 or 8.1 ? And, if I install (or updated to) W10 will it reinstall W10?

Your vendor software will reinstall 8.0 only, ever.

I suggest you just install Windows 10.

Okay, thanks.