When I was a kid, I used to always forget my house key and would have to resort to climbing a ladder and crawling through our kitchen window to let myself back into our house after school. I'm sure my mom got very tired of me knocking all her stuff off the window sill and killing the plants in the window box, but it sure beat sitting on the front porch for several hours waiting for them to get home from work.
Now that I'm an adult, I rarely forget or lose my keys, but I have managed to lock myself out of a few computers and servers more than a few times.
So the big question is:
How do you let yourself back into your computer without breaking something?
Well, I can't promise you that you won't break something, but I can give you some tips on how to hack your way back in:
Please note that these tips are for good guy purposes only, I make no guarantees that these will or won't work. It's entirely possible that you could lose all your files by trying these techniques, so use at your own risk. I'm going to guess that if you are reading this page that you are at your wits end and this is a last resort.
If you can't get into your computer because your PC contracted a computer virus, has become part of a bot net or has been hacked, then you should skip over to my I've Been Hacked! Now What? article before going any further. The instructions in the article you are reading now are meant for restoring administrator account lockouts only.
For Windows 7 / Vista / XP:
One of the best utilities is the Trinity Rescue Kit (TRK). This free (donation-ware) utility can help you recover the administrator password for your computer, recover files, evacuate a dying disk, scan for nasty root kit malware, and perform many other disaster recovery tasks.
The Trinity Rescue Kit can be loaded onto a CD/DVD or USB drive and should run when you boot the computer prior to Windows loading. You must go into your computers setup (bios utility) and choose "Boot from USB/CD/DVD" before you attempt to use this utility. If you don't set the Boot from USB/CD/DVD, Windows will launch as normal and TRK will not load. Be sure to check your PC's user manual for details on how to access the BIOS setup / configuration before attempting to use this software.
If this method fails check out this article from 4SYSOPS for several other methods of admin account recovery.
For Mac OS X Snow Leopard, Leopard, and Tiger:
Insert your OS X DVD that came with your computer or use the disk you purchased to upgrade your original OS X and restart your Mac. Hold down the "option" key during the restart until you see the Startup Manager. Double-click the "Install Mac OS X" icon. Once the installer has loaded, choose utilities and then click restart.
After the installer loads, choose "Utilities" and select "Reset Password". Follow the instructions provided in the utility to reset the admin password.
For Mac OS X Lion:
Restart your Mac and hold down the Command-R keys as soon as the restart begins. Keep holding the keys until the Apple Logo appears.
The reset password utility is hidden in OS X Lion but is still accessible. After the startup sequence completed your should see the Recovery HD utility. Once in the utility, open a terminal window and type resetpassword and press the return key. Follow the instructions provided in the reset password utility to reset the administrator password.