How to Survive the Worst PC Disasters

Problem: You can't get into Windows because you forgot your password.

Likely Cause: Consult your family physician for a complete diagnosis.

In Video: How to Retrieve a Lost Windows Password

The Fix: With each version of Windows, recovering a lost password becomes a bit harder, thanks to Microsoft's inexorable security improvements. However, there's no need to abandon hope.

1. If it's your Windows XP log-in password, try logging in under another account with administrator privileges. (There may have been an account like 'Owner' installed, often with no password, when you first bought your PC.) Any administrator account can reset the password of any other account. If you're not using the Windows XP log-in screen (the one with the icons for each user), you can try logging in with the account named 'Administrator', which is hidden on the XP log-in screen. If you are using the XP log-in screen, try pressing <Ctrl>-<Alt>-<Delete> to reach the old, NT-style screen, which should allow you to type in the user name.
2. If no other account exists on the PC, you'll need to turn to third-party tools to reset the password or crack it. Ophcrack is the first third-party tool I'd recommend to recover a lost password: Using another PC, download the free software from ophcrack.sourceforge.net and burn it to a disc. Boot from this CD and watch Ophcrack go to work. Based on extensive password tables, it can recover most passwords in a matter of minutes, for all the accounts on a PC.
3. You also can try a tool that can reset your password if everything else has failed; note, though, that such tools generally involve a small risk of data loss or corruption. Offline NT Password & Registry Editor and Emergency Boot CD are both free, include bootable CD versions, and are fairly self-explanatory if you're comfortable working with the command line. Both can reset your Windows password for you, and they support multiple versions of Windows.
4. If you lost a BIOS-level password, you can try resetting or bypassing it. First, try backdoor passwords as listed at Tech FAQ. If none works, try resetting your CMOS--as discussed in "Problem: Your computer won't boot"--to cause the BIOS to reset to its default state. Replace the battery and then restore the jumper to its original position and reboot your system.

How to Avoid It Next Time: If password loss is a frequent problem, consider writing them down and keeping them in your wallet, or storing them in a bank safe deposit box or a safe at home--just make sure you don't lose the key.

For a visual tutorial on this subject, watch our video.