Windows 10: System Protection and Restore

I recently found out that my Windows 10 pc C drive is full. When navigated found out that system restore has reserved a massive 80GB of my C drive. Then I navigated to settings and reduced that space to 20GB max. I found out that my C drive does not have system protection turned ON or any of drive. So should I turn on system protection for my C drive and what should be the sufficient space reserved for system restore .

:)

 

Is There a Way To Protect System Restore?

So I just got off trying to fix my dad's computer, for the 2nd time in a few months, because it has some kind of malware or trojan on it. The first thing I always go to to fix his system is system restore because he doesn't make many changes, if any at all, to windows, software, or basically anything system restore restores other than updating windows. But the last few times he's had various problems system restore, with either has it's restore points being deleted or restore won't even start up. So basically I really need help finding a way to either password protect system restore (preferably for free), get a 3rd restore program that won't get disabled by this malware crap, or any other alternative. I really appreciate any help you can give me because I've had this happen to a few computers that have come my way to fix and i wish there where a way to stop it.

Edit: Just found a program call Settings Lock (http://tinyurl.com/cuzen4) that I tested and it did successfully stop me from turning off system restore or changing it--but it's $25 and i'm not sure if restore could be turned off another other than my gui interface with that program so i'm still hoping to find something better or at least hear some more info about it.

 

Cannot Create System Restore Point Because Cannot Turn On System Protection

In Control Panel/System/System Properties/System Protection, "Available Drives," all that is listed is "Searching..." No drives are located, so no System Restore point can be established.

How to fix?

I have an extensive active thread in another area of the community dealing with the failure of this PC to install the latest Windows 10 update. Prior to executing the next suggested step to fix that problem I need to create a System Restore point, so a
solution to this issue must be found before I can move forward on the major problem.

YES, I have ALREADY run the SFC Command as Administrator and the report was that everything was A-OK.

 

How to delete inactive System Image Restore Points in System Restore

Windows 10 64-bit.
When I click "show more restore points" in System Restore I see a bunch of old "system image restore points" that were deleted in past and do not correspond to any currently active restore points. Clicking any of these old restore points, I simply get an error message saying they could not be found, and to select another restore point instead.I would like to delete these restore points listings but have been unable to do so.
So far, I have tried steps mentioned below without any luck :

Disk Cleanup through (C Properties
Disable System Protection (OFF and ON) in System Protection for OS (C
Disk Space Usage to minimum (slider button all the way to the left then 'Delete all restore points for this drive'),
Delete all shown Restore points in CCleaner (the problem ones do not show here),
Reset Windows Backup to Default in Windows 10 with 'Reset_Windows_Backup.bat' utility.

Any suggestions highly welcome.