Hi
If you did delete your System32 folder from the Windows directory don't reboot your computer until you get it fixed.
That's how the scheme works, you see a video that seems to show someone removing their System32 folder and saving disk space without any consequences, they don't show the computer being rebooted.
If it's really gone it won't restart, at present the System32 files are still loaded in to ram, that's why your computer is still working.
It would have resisted being deleted, (I'm not going to test it) you would have gotten warnings and had to insist a number of times for it to go ahead.
I'm not sure that it really would have deleted the whole folder without individually removing some of the components one at a time.
If you don't have a system image file then the only fix may be to do a Reset to restore Windows 10 to it's normal condition.
Since your computer is still working backup everything that you need to a external hard drive, 2nd internal hard drive, partition. or DVDs.
Save your address books, favorites, game saves etc.
You will have to reinstall all of your software.
Recovery options in Windows 10 - Windows Help
Maybe by the time you get everything backed up someone will come along with a better solution, but I don't know any other way to get it back.
But as Dave said make sure that it's really missing.
C:\Windows\System32
Mine is over 5 GB so it's a lot of files.
Mike