It depends on what you want to backup. If it's static data that won't have any problems with ownership of ongoing processes (like Outlook PST, Access databases, etc.) then rsync will work fine. You could also schedule backups run through any number of batch files to give you a similar incremental backup of files.

However, you wouldn't be able to backup the entire systems OS and running programs that way. If you need a full system backup then you need to look at drive imaging software. Drive image software takes a snaphot of your entire system, and you can then restore everything (or only selected parts) to that exact state. It's great for roll-backs, testing, and recovery. There are a number of programs out there like Norton Ghost or Acronis TrueImage that can accomplish this for you.