Can you recommend a good backup tool

Using W2KPro and running Spybot, Adaware, & various regcleaners per prior advice here. I backup modified files to CD's or the hardfile on another machine, but only copy entire directories recently changed.
I'm looking for a better tool, preferably one that can backup only changed files & keep a three tier backup set. Don't care if ti's CD or hardfile oriented.

Thanks in advance for any suggestions.

 

I prefer to do a full weekly, fortnightly or if I'm a bit lazy, monthly system backups using Acronis TrueImage 8.0x.
http://www.acronis.com/homecomputing/products/trueimage/
Whilst this isn't freeware and probably does more than what you want, I find it perfect if you do regular backups to another drive internally, seperate partition on you existing drive (this isn't recommended for fairly obvious reasons), external USB 1.1, 2.0 or firewire drive, or to CD/DVD media. It also includes incremental backups, although I've never used that function, prefering to do full backups that can be restored in as little as 15-30 minutes if the backup was done to another HD and not via USB 1.1. Backups can be performed from within windows or from a boot disk, which is my prefered method.