New
#11
Check wjhether there are really no restore points. Open an elevated command prompt and run this command:
vssadmin list shadows
Make sure you look at the ones from C. If you like, you can copy the output in command prompt here and we'll have a look at it.
Right click on the command prompt window and click on 'select all. Then right click anywhere on the hihjlighted area. That puts everything on the clipboard and you can paste it into your answer here.