A lost password: Windows includes a hidden Administrator account that can be used for problems with other accounts. You can access it by restarting the computer into safe mode.
First, restart the computer. As it starts, repeatedly press the F8 key (some computers instead require the Delete or Esc key). Instead of the familiar Windows screen, you will see a text-only Advanced Options Menu. Use the arrow keys to select Safe Mode. Then press Enter.
Select the Administrator account. By default on most computers, it requires no password. Once logged in, you can change the password of the account you normally use.
To make the change: click Start, Run.
In the box, type ‘control userpasswords2’ (without the quotes) and click OK.
Select your normal account name in the list.
Click the Reset Password button. You will be prompted for a new password. You can restart the computer and use the new password on your normal account.
If you're completely locked out of your computer, you'll need software. Such services include Login Recovery (http://www.loginrecovery.com/), FastCrack (http://www.fastcrack.com/), and NT Password and Registry Editor (http://home.eunet.no/~pnordahl/ntpasswd/). Each is free. They make use of boot disks that you can download to a floppy or burn to CD. Of course, you'll have to use some other computer to do the downloading.
Once you've got access to your computer, set a new password through Windows.
To do this: click Start, Control Panel.
Double-click User Accounts.
Select your account and click ‘Change my password.’ You'll be prompted for a new password.
You'll also have the opportunity to enter a password reminder. It should trigger your memory if you ever forget your password. But the reminder should not be descriptive enough to allow others to determine your password.