ComponentSoftware RCS (CS-RCS) is a powerful yet simple to use document management system for Windows. CS-RCS is free for single user and inexpensive for workgroups.

CS-RCS is ideally used for general-purpose document revision management as well as for entry-level software configuration management, and fully integrated with the Windows Explorer, provides the most intuitive and easy-to-use solution on the market today.

CS-RCS handles all types of documents including HTML documents, MS-Office documents, pictures, drawings and program files.

CS-RCS can use any file server or local drive to store the archive repository. Network connection to the archive repository can be LAN, corporate wide-area network (WAN), Virtual Private Networks (VPN), dial-in terminal services connection and the Internet. CS-RCS supports Internet access to remote projects by native client or any Internet browser.

CS-RCS Pro includes advanced features needed for complex software and web development projects. See here for an extensive comparison chart:
http://www.componentsoftware.com/Products/DocMan/comparison.htm