It should have a hidden partition with a stored recovery image on it where you can restore your machine to how it was the day you first bought it. Depending on which E-machine model you have will dictate which key you have to press when the machine starts booting to start it off. (Will be easy to Google this )
What makes you think you have no system restore points?
But as you state, and @hazelnut has highlighted, this is all irrelevant as you had that feature turned off.
The Windows 7 offered backup may indeed help if you had it set to include a system image of the drive.
From your TreeSize exercise, what were the names of these 3 large system files?
Actually this machine had the Restore Points turned off since I got it. I turned them on recently when this problem started.
In Oct. I was working on a Word Doc. When I went to save it I could not save nor delete it. After some trying I rebooted and the machine would not reboot. I tried a system repair but it wouldn't do that either so I did a full restore to factory default. Before that restore I had 45GB on the C drive. After all the downloads and updates etc (two days work) There was 32GB.
Then about mid Nov I noticed there was about 35GB and it was about 10% fragmented. So I ran a defrag with Defraggler and there was suddenly 38GB and it was 14% fragmented. ???
Each time I ran Defraggler this went up, that is why I came to this forum.
This has since grown to 63GB.
I only have 100GB of space on the C drive so I am concerned.
The Tree Size shows the problem is 3 Sys Files that are names with a long string of numbers/letters.