Task Manager Troubleshooting - Registry Access And Changes Denied

I am experiencing a number of Reliability and Performance Logs, and Task Scheduling issues and difficulties.

In trying to troubleshoot the problems, I have started with the Task Manager, as it is clearly not performing at all.

First, before starting this process, I created a new Restore Point.

Then, at Start>Help and Support>Select, ?Troubleshooting>in Search Help box type, Troubleshoot Task Manager>Select, How do I enable Task Manager if it has been disabled. ....I end up with this set of troubleshooting instructions;

Using Administrator Rights, I am able to navigate down to Step 3 of the instructions,[see string in bottom panel] here;

Before going further, per the instructions, I saved a copy of the Registry Key to a hard-drive.

With that done, I tried to double click on System, but nothing happens! Disable TaskMgr does not come up to allow me to continue with the troubleshooting process.