It is not something that happens very often but it might happen to you at some point. if you forget your Windows XP password or your password expires and you cannot create a new one there are several ways you can regain access to your computer, from using password reset disc, thru changing passwords via a different account to password recovery and password cracking tools.

Method 1 - Use password reset disk.

If you created a password reset disk for Windows XP, reset your password by using the password reset disk. Here is how to create and use a password reset disk

1. Click Start, and then click Control Panel.
2. Under Pick a category, click User Accounts.
3. Under Related Tasks, click Prevent a forgotten password to start the Forgotten Password Wizard.
4. Click Next the Insert a blank, formatted disk into drive A, and then click Next.
5. In the Current user account password box, type your password, and then click Next.

Note If your user account does not have a password, do not type a password in the Current user account password box.

6. When the Progress bar reaches 100% complete, click Next, and then click Finish.
7. Remove and label the password reset dis, then store the disk in a safe place.

Method 2 - Log on as an administrator to reset the password

If you cannot log on to Windows XP by using a particular user account, but you can log on to another account that has administrative credentials, follow these steps:

1. Log on to Windows by using the administrator account that has a password that you remember.
2. Click Start, and then click Run.
3. In the Open box, type the following command, “control userpasswords2″ and then click OK.
4. Click the user account that you forgot the password for, and then click Reset Password.
5. Type a new password in both the new password then confirm the new password, and then click OK.

Method 3 - Use password cracking and recovery tools.

Password-cracking tools are usually disks containing Linux operating system that have NTFS access and special application that can read the registry and rewrite passwords.
There are several free tools for Windows:

1. Offline NT Password & Registry Editor - This is a utility to (re)set the password of any user that has a valid (local) account on your NT system.

2. John the Ripper password cracker - John the Ripper is a fast password cracker, currently available for many flavors of Unix.

3. ERD Commander 2005 by Winternals allows ERD Commander 2005 boots dead systems directly from CD into a Windows-like repair environment. You’ll have full access to the dead system’s volumes, so you can diagnose and repair problems using tools located on the ERD Commander 2005 Start menu. And you’ll have built-in network access to safely move data off of, or on to, the dead system.

4. CIA Commander 2 by datapol also gives you thegives you the ability to boot locked or dead Windows systems within seconds! The CIA Assistants within Commander 2 offer help in a Windows like GUI for retrieving lost or forgotten passwords, accessing NTFS directly from CD, repairing the registry and windows system, cleaning viruses and even starting and repairing Windows from bluescreens.

5. EBCD – Emergency Boot CD - EBCD is a bootable CD, intended for system recovery in the case of software or hardware faults. It is able to create backup copies of normally working system and restore system to saved state. It contains the best system software ever created, properly compiled and configured for the maximum efficient use. It can change password of any user, including administator of Windows NT/2000/XP OS. You do not need to know the old password.

6. Proactive System Password Recovery - Proactive System Password Recovery (PSPR; former Advanced Windows Password Recovery) by Elomsoft is a program to recover most types of Windows passwords as well.