Windows system restore point files can consume HUGE amounts of disk space

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:

1. Open the System Protection tab of Disk Cleanup and click the System Restore button.
2. 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.)
3. 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.