1. Boot using Windows XP Setup CD and follow the instructions including Accepting EULA, etc. 2. When it asks to repair your existing Windows installation, accept it and press "R" to run the repair. 3. Setup will start repairing your Windows and will start copying files, etc. 4. After a few minutes setup will restart your system and when it restarts don't press any key when it shows "Press any key to continue..." otherwise Setup will start from the beginning. 5. Now it'll start doing other tasks and will show a small progress bar with a few details in left side. 6. Look carefully at the details and when it shows "Installing devices", press +F10 keys in your keyboard. This is very important. 7. It'll open a Command Prompt window. Now type nusrmgr.cpl and press . 8. It'll open the same "User Accounts" window that you see in Control Panel. Now you can remove or reset any account password without any problem. 9. Then, you can gracefully wait for the repair to finish, reboot, and login with your changed password. If you cancel the repair, the changes will be lost.All you need is access to Windows XP installation media and the system to boot from the CD Drive. After this, I remembered some of my newer systems come with a boot partition and allow me to essentially run this procedure without a CD at all. All I need to do is interrupt the boot process and select the alternative Recovery Partition to initiate the same changes. If you are trying to secure your system(s) and cannot limit physical access, consider the following steps to make sure procedures like this will never work:
1. Disable all removable storage devices and CD/DVD ROMs in the BIOS and Operating System. (Endpoint Protection tools can assist with this for the OS.) 2. Use a password to protect the BIOS from Modifications 3. If warranted, encrypt the hard disk with BitLocker or a third party disk encryption software so external boot devices can not read or edit the disk 4. Secure the PC. Use a lock or cabinet to secure physical access so ports and cables are not accessible to end-users.Note: Consider item 4. If a newer flat panel is used that has USB ports, consider not using the cable to activate them. It is an easy way to plug in a thumb drive and copy information off the system without ever touching the physical chassis itself. Physical and password security go hand-in-hand. There are many easy tricks to crack a password when a user has physical access to the host so consider also securing the device if the information contained within is valuable to your business.