I heartily recommend SystemWorks if you are interested in having such advanced troubleshooting/maintenance tools at your disposal.
Many people complain that SW or NU slow their systems down too much. I agree but all it takes to fix this is to remove the system monitor tool (the icon looks like a traffic signal) from the startup folder in your start menu. The benefit of this monitor (without serious tweaking) is rather dubious when weighed against the performance penalty.
As for the drefag tool, you get a whole slew of options unlike the MS OEM tool.
The registry cleanup tool works very well, too.
Norton Antivirus is definitely the best all-around weapon against infection McAfee users, please consider the ease of updates before you start flaming me. My experience is that my clients who use NAV update MUCH more often than my clients who use McAV. That is a pretty solid telling of ease of updates, the number two factor in staying virus-free.
Ghost is a pretty decent HD backup tool. I run Ghost from the command line and break my image files into 695MB chunks so they fit on a CD-R. That way all I need to to do a full system restoration is a boot floppy with Ghost and CD-ROM drivers and a set of backup CDs. My roommate regularly restores 6-7GB of data this way when he breaks his Windows installation. He has a good stable configuration with all his favorite software already installed on the backup CDs.