If you backup your files to a location such as an external hard drive or network share then you may want to look into synchronizing your data rather than just copying and pasting the files over themselves each time you backup. Plus if you want to make sure that files you deleted on the source are deleted on the destination then synchronization is definitely something to think about.
Microsoft SyncToy is an easy to use, customizable application helps you copy, move, rename, and delete files between folders and computers.
Most common operations can be performed with just a few clicks of the mouse, and additional customization is available without added complexity. 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. Unlike other applications, SyncToy actually keeps track of renames to files and will make sure those changes get carried over to the synchronized folder.
SyncToy offers the following options to synchronize your folders.
Synchronize - New and updated files are copied both ways. Renames and deletes on either side are repeated on the other.
Echo - New and updated files are copied left to right. Renames and deletes on the left are repeated on the right.
Subscribe - Updated files on the right are copied to the left if the file name already exists on the left.
Contribute - New and updated files are copied left to right. Renames on the left are repeated on the right. No deletions.
Combine - New and updated files are copied both ways. Nothing happens to renamed and deleted files.
SyncToy will run on Windows XP and up. Click here to download.