Firstly,Windows is installed on you computer and then you need a live CD of linux, here we will use a live CD of UBUNTU.

Boot from the Live CD and perform the 7 easy step to hack the windows Admin password.

Steps:

1: Install a program called chntpw

Command is: $ sudo apt-get install chntpw

The rpm package installed is the package to change password.

2: After successfully installing chntpw, you have to access the Windows NTFS partition by mounting it and allowing read/write            support.

Use Mount system Call.

3: After that, navigate to WINDOWS/system32/config

use cd command to navigate.

4: Once inside the config directory, issue this command:

$ sudo chntpw SAM

Command to reset admin password.

As you are in Linux the security of windows is bypassed and the password can be changed easily.

5: A long display of information will follow.

Just ignore them.

6: Once you are prompted to reset the password, it is recommended to leave the password blank with an asterisk (*).

7: Reboot, with windows and you can now login to Windows with full administrative access.