Here we will see two type of password bypassing for windows

1.using ubuntu live cd and chntpw command

2. using offline nt password recovery cd or usb

  1. Use chntpw to delete a Windows password : With chntpw utility, you can erase the password of      any Windows account, freeing access.first load the ubuntu live cd and linstall chntpw .
  • Open a Terminal window by clicking on the Ubuntu menu, click Accessories, then Terminal.
  • Enter the command cd / media and confirm with Enter.
  • Enter the ls command and confirm with Enter. The list of hard disk drives is displayed. You should see the reference noted above.
  • Then enter the command cd followed by the reference hard drive containing Windows. In our case, the command is cd FAC4AC2BC4ABE7D9. Confirm with Enter.
  • Then type the command cd WINDOWS/system32/config to access the Windows system folder where are saved passwords. Press Enter.
  • Then enter the command sudo-i chntpw Sat and confirm by pressing Enter.
  • Press the button 1 and press Enter.
  • SAM is the file that contains the Windows registry. The list of users on your system is displayed. Enter the code located in the RID column beside the name of the user you want to reset the password to zero code preceded by 0x and press Enter. For RID 03E8, the command becomes 0x03e8 here.
  • Then press the 1 key to erase the password for the selected account and confirm by pressing Enter.
  • The password is then deleted as you said the message Password cleared. Press! And press Enter to exit from the menu.
  • Then press the q key, validate and confirm the registration of the change by pressing ahead. Confirm with Enter.
  • Then close the Terminal window and restart your computer by clicking the Stop button and then click Restart. Confirm the operation and remove the Ubuntu CD in your drive when you are asked. Press Enter.

2. Offlint nt password recovery(http://pogostick.net/~pnh/ntpasswd/)

first download the cd or usb zip files form below and follow the steps

http://pogostick.net/~pnh/ntpasswd/cd110511.zip

http://pogostick.net/~pnh/ntpasswd/usb110511.zip

cd…if u r using a cd then simply  download the iso and burn it in the cd and use it

usb…

  • Copy all the files that is inside the usbXXXXXX.zip or on the CD onto an usb drive, directly on the drive, not inside any directory/folder.
  • It is OK if there are other files on the USB drive from before, they will not be removed.
  • Install bootloader on the USB drive, from command prompt in windows (start the command line with “run as administrator” if possible)Replace X: with the drive letter the USB drive shows up as (DO NOT USE C:)
    • X:syslinux.exe -ma X:
  • If it seems like nothing happened, it is usually done.
  • However, a file named ldlinux.sys may appear on the USB drive, that is normal.
  • It should now in theory be bootable.

now use the cd or usb to reset the password use the walkthrough if needed http://pogostick.net/~pnh/ntpasswd/