I have applied some changes on my PC through the group policy(gpedit.msc), for example, disabling "Hide Desktop Tab" under the Display setting in the Control Panel section, but everything seemed to remain the same and the "Desktop" tab in the Display Properties also didn't appear as expected.

Another problem is that I had applied the "Restore Default" in the "General" tab of Folder Options, but when I open it again, all the options still remained the same as the original(before I restore default).

What's the problem?

Tried rebooting?

do you have administrator rights?

Yes, I have the right, so ?