I have 2 USB hard drives with supposedly identical copies of my music library. Periodically, I use Microsoft Synctoy to ensure that everything is mirrored properly between the drives. That way, if I have problems with one of the drives, I'll still have everything on the other drive.
Last night, Windows decided it needed to run chkdsk on one of the drives. It found a few messed up files in one directory, which it deleted. Now I run synctoy to, among other reasons, restore the files from the good drive. Good thing I always run in preview mode so I can look at the steps before it does them. SYNCTOY WAS PLANNING TO DELETE THE FILES FROM THE GOOD DRIVE!
Typical of Microsoft, their tools do the opposite of what you want. Microsoft would probably make the stupid claim that synctoy WAS bringing the disks into sync by deleting the files. Next time I buy a Microsoft product, maybe I should ask the store to pay me the purchase price rather than pay them!
Oh well, I guess synctoy, unlike other Microsoft products, is worth what I paid for it: $0.