[pjc50]

This is what "System Restore" is for: https://support.microsoft.com/en-gb/windows/use-system-resto...

It looks like they're all registry modifications, yes.

[httpsterio]

I have had issues where a restore point didn't revert certain registry settings and have had to do a full reinstall.

[thunderbong]

Can you give some more info? Which version of Windows? Because I've never had a system restore go crazy unless a hard drive has gotten corrupted.