I know this is an a known issue, and I have read all of the guides in the troubleshooting section on why running Defraggler could cause less free space, and followed all of them to prevent it... but they didn't help, it's still happening to me.
I had 181GB free on a 2TB drive. I ran Defraggler, and suddenly I was at 165GB free. I looked up the guides that mentioned VSS and restore points being the cause, and followed all of them. I disabled VSS in Defraggler, I used Disk Cleanup to delete all shadow copies and restore points, and even went into the restore points tool and deleted any remaining restore points from there as well as used CCleaner to clean up any temp files, but it didn't seem to help.
After all that, I was left with 200GB free. So I tried running Defraggler again.... and now I am back at 165GB left free. Disk Cleanup/System Restore is telling me that I don't even have any restore points left on my system now to delete, CCleaner also says there are only 6 megs of temp files on my system, the free space is just gone.
