That's what I was hoping for too, but no luck!
As you've got an external HDD and a second computer, I'd seriously look into some sort of automatic or semi-auto backup routine. I'd also look at making a backup of your system partition once you've got the computer reloaded with all the software.
I get Personal Computer World magazine, and the free CD includes some great software - they've given away Acronis True Image and Paragon Disk Backup - full working copies - that allow you to setup your PC, and before you have time to screw it up, make a backup. Load and update windows, add firefox and your favourite anti-virus software (do this early so that you can download the updates etc.), and any other often used or critical software. Set up your email, internet access, e-mail etc. Then make a partition backup to the external HDD, and an emergency boot CD. Then, next time windows gets screwed, you should be able to take it back to that state in a few tens of minutes. Invaluable! And for not much more than the price of some space on an external or network disk.
RAM sticks are so cheap and big now that you could probably back up all your documents on a regular basis. Again, there are a lot of options for this, but I'm a luddite, and I like "Update2.2" from profiles software (http://www.profiles-software.com
) - it's low tech, but it allows you to set up a simple command file that will copy all files from A to B, (a simple copy, no compression or anything) and after that, it will just copy files that have changed. The first run takes a while (20mins for a few gig?) but after that, it just takes a few seconds. Your pictures, music and e-mails may need more work, but you can set up automatic backups for those too (as you already have, although possibly not 100%)
Me - I'm just hoping that the 3 PC's with this problem that I've fixed in the last week stay fixed!