Updated version of Microsoft SyncToy
Two years ago, Microsoft added SyncToy to its PowerToys collection. It has now been updated to version 2. The tool is designed to keep the contents of two different folders synchronized. It is useful as a folder backup or for using a thumb drive to keep the contents of folders on different computers the same. It’s a little heavy-handed since it uses certain SQL server components but comments on the Web are reasonably favorable. Personally, I use my own little program or Karen Kenworthy’s Replicator but you might like to try this free Microsoft offering. Download is here.
Addendum: Be prepared for the fact that SyncToy is very slow.