Windows only: Free snapshot backup utility DocShield provides a similar service to previously-mentioned FileHamster, but with a lot more control over how often, and how big, those backups should be. Select individual files or groups of certain file types (like .jpg or .xls in the My Documents folder, for instance) on your home computer, networked systems, or even remote FTP servers, set DocShield to check at certain increments, and choose whether those backups are compressed or not. Better still, the program offers a utility to save a file and its versions onto a USB drive, along with a utility to read and re-save it. For those looking for a Time-Machine-like utility for Windows but don't need entire systems backed up, DocShield is a helpful tool. DocShield is a free download for Windows systems only.