An interesting topic…
Once I had my TR3A for a little while I did a clean install of Win XP Pro, got all the drivers and hotkey/camera stuff working. Then I installed my “base” applications, Office, Quicken, image viewers, etc.
I used Drive Image to create an image of that drive and then put that image onto a DVD. Anytime I want, at least a couple times a month, I can restore back to that image in about 10 minutes.
This allows me to play with software and downloads and then be able to restore very quickly back to my good setup.
I went to a web page one day which insisted on installing some software on my computer even though I said no. It completely hosed my system, made Explorer crash every time I started it, installed spyware and some non-spyware. I had my backup and was able to restore my system.
My data and other non-OS files are stored on seperate partitions so I don’t have to worry about them.
If your computer is important to you in your daily activities (work, play, whatever), you should have some sort of method of quick recovery to minimize downtime when something unexpected happens.