Open Control Panel, open System, go to the System Restore tab, select the C
drive, click settings and be sure space is allocated for System Restore. If
yes, open Explorer, select the C drive and be sure you have enough free
space. If you have too little free space there may not be enough room on
the C drive.
If you have enough free space, return to the System Restore tab, select
"Turn off System Restore on all drives," click apply and ok and reboot. Now
return to the System Restore tab, remove the check and reboot. This will
delete all current restore points but should reset the system so all drives
are protected and should certainly get the C drive protected again. Once
you've completed this operation, you might want to create a manual restore
point and then restore to it to be sure it is now functioning properly.
