Good question.
However, here is how I maintain redundancy as such.
I Installed my OS. Fully patched up and tweaked it.
I installed the most efficient drivers for my hardware. Not necessarily the
latest ones.
AV and Firewall were installed and fully patched up.
I installed my most used applications and utils etc.. and tweaked them.
I ended up with roughly 3Gb or so of OS, Apps, Utils and Security apps.
Before installing Each driver, set of updates and application. I created a
System restore point. That way if the whole thing screwed up when I
installed an app or driver or "Microsoft Update", I could restore back and
it's all good again.
Once EVERYTHING I need was installed and set up exactly how I like it, I
created a complete image of my system using Driveimage 7.0. This got saved
onto a DVD-RW.
So, if my system starts being retard, if possible I back up any new data I
need to, Emails, Docs etc.. across my LAN to another box. (Virus checked of
course). Then, with Driveimage, it's about 20 minutes to get back to fully
working order.
From there on, I re-install any new apps, utils etc.. that I may have
installed since initial installtion, patch up with the latest updates all
round since initial installation and carry on from where I left off.
System Restore is very good at what it does. I ALWAYS create a restore point
before installing ANY update, driver, program etc.. On occasions after
installing a video driver (Nvidia), I've restored back to the point I
created just before installing because the latest driver is rubbish or
something. No problems, sweet as.
)
If used correctly, Sys Restore and Drive image are fantastic.