Yes, ComboFix disables autorun because some malware uses it. It should have been enabled by the registry fix, but for some reason that didn't work.
I think if it were me I would leave it as is, but if you want, there is another tool you can try: Ultimate Windows Tweaker.
There should be a setting -> Security Settings, Administration Restrictions, Disable Autoplay for Removable Devices. I think if you check the box to disable, then click apply, then uncheck it and click apply again, it may set it back to default. There is also a Restore Defaults button you could try if you wished. You need to reboot after making the changes.
If you don't want to try that, I can give you a reg fix that will undo what we changed before.