It was bound to happen with all those numbers floating around in your brain – you've forgotten your Windows password. Here's how to recover it.
At the Windows login screen, click on the question mark. If you entered a hint when creating your password, a pop-up bubble will display it. Rack your brain for anything that relates to your hint, and type it in as a password.
If you never included a hint or are still stumped, try connecting as an Administrator. At the login screen, press Control-Alt-Delete twice, then type in "Administrator" with a capital A as the user, and leave the password blank.
If you're able to log in, right-click on My Computer and select Manage. Click on Local Users and Groups and then Users. Right-click on your username and select Set Password. Fill in the field with a new password.
If you can't log in as an Administrator, you'll have to do things the hard way. Load your Windows operating system CD and restart your computer. When prompted, press any key to boot from the CD.
When the Setup screen appears, press Enter to set up Windows and then press F8 to accept the licensing agreement. Choose the Repair option on the Setup screen.
Allow a few minutes for your computer to complete the repair process. It will reboot automatically when finished. After a few minutes, when the Installing Devices progress bar appears, press Shift-F10 to bring up the command console.
At the prompt, type in either NUSRMGR.CPL or userpasswords2 and press Enter to access your user account. Select your account and change your password – preferably to something you'll remember. Exit the command console and enter the Windows Product key from your original software if you're prompted.
When your operating system starts up again automatically, log in with your new password. All of your files and settings should be intact.