SyncToy is a free PowerToy designed by Microsoft, that provides an easy to use graphical user interface that can automatically synchronize local or network files and folders, but not WebDAV-, "Windows Mobile" files or folders and no triangle-sync as only Allway Sync or GoodSync can do. SyncToy can manage multiple sets of folders at the same time; it can combine files from two folders in one case, and mimic renames and deletes in another case. Unlike other applications, SyncToy actually keeps track of renames to files and will make sure those changes get carried over to the synchronized folder.
