How to Fix Your Relatives' Terrible Computer

Turning on the computer results in a message that states Windows can't boot because something is missing (a boot loader, an important file, etc.) or something is wrong. There are many variations on this message, but they all say basically the same thing: You will not be getting into Windows.
If this is happening on an XP computer, consider this a great opportunity to talk with your relatives or family friends about upgrading to Windows 7. Seriously. Read up on what you'll need, learn how you can transfer settings from XP to Windows 7, and dig around for any discounts they might have coming—particularly if there's a student of any strip in the house.

Quick-fix triage (for non-booting systems you might be able to restore): Load an XP, Vista (if you must), or Windows 7 (Really? Broken already?) CD or DVD in the system and boot the system from there, which might require hitting a key to bring up "boot options" or pressing a key when asked to "Press any key to boot from CD." Wait for the CD to load—it may seem like it's installing, but it's just loading a mini-system for installation and, in this case, repair. Follow the prompts to repair an existing installation, or, in the case of Vista or 7, ask it to repair the startup process. What you'll need:

• XP, Vista, or Windows 7 installation CD/DVD: It may be from a computer manufacturer and not look like a Microsoft-obtained, holograph-packed disc, so look around a bit. If it's a "System Restoration" disc, be sure that you can boot from it and install a full copy of Windows from it.
• USB thumb drive: At least 1GB in size.
• External USB drive or blank DVDs: For backing up important files.
• Ubuntu Live CD or Knoppix Live CD: Both are Linux distributions, but we're just using them because they run on most kinds of hardware without installing, and can transfer the files you need to your backup media. Ubuntu should work; if it doesn't, give Knoppix a go. You can use the free tool UNetBootin to transfer the ISO you downloaded to a thumb drive, which is necessary if you're backing up to DVDs, and recommended in any case to speed things up.