Many months ago, I trialed Comodo's Time Machine (CTM; forum at https://forums.comodo.com/help-ctm-b197.0/). It showed promise but had lots of problems so it was too flaky to waste time using and I wasn't interested in QA'ing their product over a long time (since the dev resources seem to fluctuate a lot to reallocate them to different projects). One of its problems is that it would save the snapshots on the hard disk in the same partition as the operating system but hide its disk usage. The result was that Windows would see lots of free disk space that really wasn't there, and CTM would interfere with Windows using that disk space to preserve the integrity of its snapshots. Users requested an option to save the snapshots in a different partition perhaps one setup solely for storing the snapshots. A side effect is that these snapshots, if in a partition on a different hard disk, would survive the disk failing on which resided the OS partition. That is, like with my own image backups, I put them on a different hard disk. If the disk with the OS partition dies, I replace that hard disk and restore an image from the other hard disk where are my backups. I'm down until I replace the OS disk. If the backup disk dies, the OS continues to run and I get a new disk to start saving backups again. Backups are delayed until I get a new disk but the OS keeps running. As I recall, it was NOT an option so the snapshots were getting saved in the same partition as the OS. So if that partition became unusable (disk corruption, hardware failure, malware, whatnot) then the user cannot restore their OS to a prior state. When that partition is gone, so is the OS and all the snapshots on it. It seems the Multi-Snapshot saves its images in the same partition as for where is installed Windows. So we're left with the same vulnerability of losing the entire OS if that partition becomes unusable or unavailable. However, my greater concern is stability of Windows when a kernel-mode driver is making disk writes that are hidden from Windows. With CTM, normal system calls through the Windows API would not find the files. As such, disk utilities couldn't see them. That mean the space consumed by the snapshots got corrupted when the user manually ran or scheduled a disk defrag. As I recall, CTM interfered with this which causes errors in the disk apps. There were so many problems with CTM that I didn't waste time keeping it on my host (which was my test host since I already read about so many problems that I never trusted it on my production host). CTM still seems way too flaky to even think of using it on my host. Hopefully Multi-Snapshot Tools doesn't head down the same paths and have the same problems regarding instability and corruption.