Defraggler versus Microsoft Optimizer in Defraggler Bug Reporting Posted November 14, 2019 @ElChabi: - Run Antibody's WIZTREE. It will tell you the size of the folder called "System Volume Information". In that folder the System Restore Points are stored. That folder could be VERY large in size. That folder could easily occupy 50% or more of your disk. - Solution ? Remove one or more System Restore Points. If that doesn't work then disable System Restore Points, reboot, and (if you want) enable System Restore Points again. That should free up A LOT OF disk space and could reduce the disk fragmentation.