AceBackup is a free backup utility for Windows 98 through XP. The program used to be commercial software, but the company recently set it free. You can use AceBackup to back up your data to a local or network drive, an FTP server, or to an optical disc.

The backup utility supports 256 bit encryption, file compression, and scheduled backups. There's also a feature that lets you launch an application before and after every backup, which would be useful if, for example, you want to run a disk cleaning application.

AceBackup also support for backing up multiple versions of your files. If AceBackup finds the same file in the source and destination folder, you can choose to replace the destination file, overwrite it only if it's older than the source file, or create a new file. If you have documents that you frequently update, but might want access to older copies, this feature can be a life saver.

[via gHacks]