Reset Win10: unable to reset?

We have an older computer that we are trying to reset windows 10 on so we can give it to a friend.
But when we try to reset it, we get a windows that says "unable to reset".
How can we reset windows 10?

Why not wipe the hard drive and do a clean install?

I don't have install disks, it was upgraded during the free period.
It is on a Surface Pro 2 (not that it matters)

You can download the Windows 10 installation ISO file:
Windows 10 ISO Download

Then make a USB flash drive to boot the Surface Pro 2 from:
USB Flash Drive - Create to Install Windows 10

Clean install tutorial:
Windows 10 - Clean Install

Normally when the built-in reset fails it's because the files required have gotten corrupted or are missing.

And you might want to have this download saved on a USB drive too:
Microsoft - Surface Pro 2 download

Thank you! :)