Questi tool servono a craccare la password di administrator di XP.
Traduzione in italiano a breve!

1. Ophcrack
The Ophcrack Windows password cracker is by far the best free Windows password recovery tool available. It's fast and easy enough for a first time password cracker with a basic knowledge of Windows.
With Ophcrack, you don't need any access to Windows to be able to recover your lost passwords. Simply visit the site, download the free ISO image, burn it to a CD and boot to the CD. The Ophrack program starts, locates the Windows user accounts, and proceeds to recover (crack) the passwords - all automatically.
In a test on my PC, Ophcrack recovered the 7-digit password to my administrator account in two minutes.
http://ophcrack.sourceforge.net/

Windows ophcrack-win32-installer-3.1.0.exe (Win 2000, XP e Vista)
ophcrack XP LiveCD ophcrack-xp-livecd-2.1.0.iso
ophcrack Vista LiveCD ophcrack-vista-livecd-2.1.0.iso

2. PC Login Now
The aptly named PC Login Now is the fastest Windows password recovery tool I've tested. PC Login Now doesn't actually "recover" your password - it erases it. With a blank password, you simply log on without entering a password at all!
Like Ophcrack, you don't need access to Windows to be able to recover passwords. Just visit their website, download and burn the ISO image, and then boot from the CD. PC Login Now starts automatically and resets the password to any account on your command. It's absolutely that easy.
In my tests, PC Login Now instantly cleared the password to an administrator account on a Windows Vista PC. I also tested this password recovery tool in Windows XP where it was 100% successful as well.
http://www.pcloginnow.com/
http://downloads.sourceforge.net/pcloginnow/PCLoginNow_Full_2.0.iso

3. Cain & Abel
Cain & Abel is a free, fast and effective Windows password recovery tool.
Unlike Ophcrack or PC Login Now, Cain & Abel is a more traditional software application and does require access to Windows under a particular user account. Due to this fact, Cain & Abel is often a valuable resource to recover passwords to accounts other than the one you're using, including the administrator account.
Cain & Abel should only be used by more experienced users because of its more complicated setup and other advanced features.
In the best of my tests, Cain & Abel recovered the 7-digit password to my administrator account in eight minutes.
http://www.oxid.it/cain.html
Download Cain & Abel v2.0 for Windows 9x
Download Cain & Abel v4.9.23 for Windows NT/2000/XP
View Cain & Abel on-line User Manual

4. LCP
LCP is yet another free and very effective password recovery software tool for Windows.
Like Cain & Abel, LCP is a standard Windows program you download from LCPSoft's website and install inside of Windows.
LCP can be a little intimidating to those new to password recovery tools so some prior knowledge is very helpful to avoid even bigger problems with your PC.
In my test with LCP, my 7-digit administrator password was discovered in just under ten minutes.
More Info

5. John The Ripper
John the Ripper is a very popular free password recovery tool that can be used to find Windows account passwords.
While the password recovery application itself is free, the wordlists used by John the Ripper to discover passwords do cost and are required for the software to work. There may be free wordlist alternatives that work with John the Ripper but I have not tested them.
John the Ripper is operated at the command line making it a password cracking tool reserved for the very advanced user.