Beware, this might well happen to you on a Windows system!
Refer to the following Microsoft Community user query:
Windows 7: System Volume Information has many large files ...
Today I just noticed on my Windows 10 Pro system that my 250 GB Samsung SSD was unexpectedly running out of space. I assiduously do a disk cleanup every few months, but today I discovered only about 12 GB was left when I would normally expect around 70 GB of free space.
A little analysis showed a similar situation to the screenshot above, there were more than 80 GB of system restore files.
I suspect that the System Restore settings might have been changed during a recent Windows update. I have no proof of this, but I certainly didn't myself make any change to the settings.
All that I had to do to make lots more space available was:
- Open the System Protection tab of Disk Cleanup and click the System Restore button.
- Move the Max Usage slider slider across to the left as far as I felt satisfied with. (I chose 30 GB, for no special reason, just an estimate that this would be sufficient to store the latest four or five restore point files.)
- Click the Apply button.
Note that I did not have to reboot Windows 10 or do anything else. The space was immediately freed up, and now there’s 90 GB available on the C: drive.