Free space is being eaten up by this program! How do I reclaim it?!

I ran the portable version of defraggler, and on the drive analysis, it came back that that my drive was 17% fragmented. At the start of the 1st attempt at defragmenting, the free space on my C drive was 103.7 GB.

5 hours later, it was hung on 86% defragmented, so I stop the process and closed the program. I noticed that the free space went down to 98.7 GB. I read in this forum that it could be system restore/shadow copies, so I ran both CCleaner and the windows Disk Clean up utilities, and I only gained about ~0.5 GB from that back in free space.

I restarted Defraggler. It is now at 76% defragmented, and my free space is down to 92.9 GB. Where is this 11GB going? How do I get it back?

Ok...I let the program complete, and the final free space is 91.8 GB

However, I did some googling, and noticed that there were two large files for C:\System Volume Information. Since I did not have access to the current restore point, I made a new one so I could delete the ones that was showing up in defraggler. And now I am back up to 106GB :lol:

Hopefully it won't create as large as files when I use it on a relative's computer, at it only has ~ 20 GB free space.