To crack Windows XP password we'll use a program called Ophcrack
Well,
 to crack a password there is one big science discipline called  
cryptography. Here we won't get into details but rather explain how this
 program  works.
So, if you lock your account in Windows with a password for example admin,
  here is what happens. Windows takes that password and encrypts it with
 one of  the methods of encryption and then saves it into a file(with 
Windows XP it's a  SAM file located in system32). Now your password is no longer stored as  admin, but rather something like 5fsujf92+*?sdwfhsa=)seqv , depending  on the encryption method. However, we ask ourselves, why don't we just take that  encrypted password and decrypt it back to admin.
 The thing is we can't  because it's a one way encryption and that is 
actually the point of it all. So  how do we actually crack it?
There is a number of methods but the most famous one is brute force attack.  Brute force actually means to start with a letter a and encrypting
 it.  Then see if the encrypted strings match. If not then b, c, until 
we've gotten  to admin. Then the encrypted strings will match and we'll 
know that is the right  password. Brute force attack is the slowest 
method of cracking, but there is no  risk that you'll not find the 
password. The thing about brute force is that the  time of cracking 
rises rapidly depending on how long the password is, how many  characters are being used in it and so forth.
Other
 methods, such as dictionary attack and an attack using rainbow tables  
are a better option. Ophcrack itself works using rainbow tables and 
brute force  combined.
1. Download  For Windows Ophcrack LiveCD  
Download For Vista Ophcrack LiveCD
2. This program is now an ISO image.
 Just burn it with Nero or whatever  you're already using for burning 
images( for burning only ISO images download  this burning program -  ISORecorder)
3. Now reboot your computer with the CD inside (if the CD will not boot you  need to set the boot priority inside BIOS, so that the CD-ROM is the first in  the list)
4. A menu like this will appear:
Select the Ophcrack Graphic Mode
5. After the CD is done loading, a user interface like this will appear:
The last right column are the passwords for the given users.
Now depending on many reasons, the cracking of the password could take a long  time.
Now just reboot your computer and log into Windows :)
Tags
windows

