Q. How do I prepare an emergency boot disc so I'm ready in case Windows becomes unbootable?
A. Alas, the days when Windows came with a program for creating a useful emergency boot floppy are long gone. And those old boot floppies wouldn't help with XP or Vista - even if you PC had a floppy drive.
Boot from one of the discs that came with your PC, and examine the menus (don't select anything that might wipe your drive). You're looking for emergency utilities.
You're in real luck if you have a full Windows XP CD or Vista DVD. These come with great tools for diagnosing and repairing an unbootable PC. In fact, if you don't have a real Windows disc, find one you can borrow in an emergency. Don't install Windows from a borrowed disc, but if it has the same version of Windows as your PC, use its repair tools.
Boot from an XP CD, and press R at the 'Welcome to Setup' screen to see the Recovery Console, a DOS-like command-line environment with a number of useful utilities. Consult 'What to Do When XP or 2000 Won't Boot' for additional details.
If you boot from a Vista DVD, click Repair your computer to open the System Recover program. There you'll find options to automatically fix boot problems, restore your hard drive from an image backup, diagnose memory, or perform a system restore.
If you're ready for a Windows alternative, try Puppy Linux, which you can download as a ready-to-burn .iso file from the Puppy Linux website. Boot from the CD, and you'll have a nongeek's version of Linux running on your PC. Puppy Linux is the best tool I've found for one extremely important job: copying important files off an unbootable hard drive. Unlike UBCD4Win, Puppy recognises USB drives, making it extremely easy to put these files where you can readily access them.