if the issue with the restore files being "missing" is just due to corrupt OS data\files
you should be able to repair or replace them easy enough with the SystemFileChecker tool
and\or the installation media.
8.1 is far more stable than 10.
all i saw for a long time was complaints about how terrible 8.1 was for most users.
now i almost never run into anyone currently using it.
for the couple years i used 8 & 8.1 i had nothing but issues with the desktop, start menu, and widgets constantly freezing.
Windows installer failing and crashing while installing basic applications and drivers over and over.
constant crashes with reports of system file errors.
updates failing and totally corrupting the OS.
that was when i started keeping my own separate OS drive backups, which has become a common practice for me every week or so for quite a few years.
i switched back and stayed with 7 as long as i could until a lot of the applications and games just did not offer any further support.
but with 10 i've had a great experience, once i got used to the new Start Screen setup anyway
have only had to fresh install when changing motherboards, not for OS issues.
have only had a few corruption and device initialization issues where the install package repair tools always worked to fix them.
hopefully 11 will turn out to be a better standard option for all of us out there...