I present now a way to reset the administrator password for Windows systems (XP, Vista and Windows 2003).
Ubuntu has become undoubtedly the most used distro in the world. Its ease of installation and use make it perfect for all users. Not even to install, just download the ISO image and make a CD (Live CD).
Here's how to reset the pwd Windows with Ubuntu:
(Internet connection required)
1. Go and download the latest Ubuntu ISO bootable.
2. Burn CD
3. Use the Live CD and you boot the live operating system.
4. Go to System> Administration> Synaptic Package Manager.
5. Then Settings> Repositories
6. Once the window 'Software Sources' appears, select 'Software restricted by copyright or legal issues,' and click 'close'.
7. Click reload in synaptic package manager.
8. Click Search, and type 'chntpw'.
9. Once the application 'chntpw' was found, right click and click 'mark for installation'.
10. Click "Apply Online Summary Window" and confirm the changes.
** Remember that the Internet connection is required .**
12.Poi, we must now mount the drive where Windows is. In Ubuntu, go to Places> and select the appropriate drive.
13. The last step is to reset the password using the Linux terminal.
14. In Ubuntu go to Applications> Accessories> Terminal.
15. Type 'cd / media/disk/WINDOWS/system32/config /' in the terminal window.
16. Type 'sudo chntpw SAM'
17. This will change the default administrator's password, but if you do it for a particular user, then type 'sudo-u username chntpw SAM'.
18. You will see the information. Ignore them.
19. The possimo step is to reset the password, you should keep a blank pasword using an asterisk *.
20. Confirm everything with 'Y' and then reboot.
Source Work4net
Complex but interesting