Recent Updates and Permissions questions

I need to know if the recebt updates (after Windows Installer 3.1v2) change
the registry perms and to what.

I ran a program that changed them today and now I don't know if the updates
I finally installed changed them or the updates did.

For HKCR, it changed to only one group, Everyone, abd that group has full
access for theat hive.

I want to put it all back, but if I use system restore, won't that revert
all the updates?

Will that even fix the perms issue?

Maybe an updates wants them this way now?

Thanks,
Tom