If you have forgotten your administrator password for Windows, worry not - you don't have to do a fresh install of Windows. You can use a Ubuntu Linux live CD or live USB to reset the password. This tutorial will show you how to do that, step by step.
This method works for Windows 2000 and later versions, including Windows 7.
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Note: If you have files on your hard disk encrypted using built-in Windows encryption, they may not be available after changing or resetting the Windows password using this method.
chntpw is a program which runs uder Ubuntu and lets us manipulate Windows passwords. It may not be included in Ubuntu disc. so, first, we have to install this. Below are the steps to install it (for 32-bit versions of Ubuntu only).
Boot up Ubuntu. Open up Synaptic Package Manager by clicking on System at the top of the screen, expanding the Administration section, and clicking on Synaptic Package Manager.
click on Settings > Repositories in the Synaptic window.
Put a checkmark if not already made on the box labeled "Community-maintained Open Source software (universe)" and then click close.
Now, In the main Synaptic window, click on the Reload button. A similar window as below will appear.
When download complets, type chntpw in "Quick search" text field.
Click on the checkbox near the chntpw name. Click on Mark for Installation.
Now, In the main Synaptic window, click on the Apply button.
You will be asked to accept the changes you have made. Click on Apply.
The changes should be applied quickly. When they're done, click on Close button. chntpw is now installed and ready for use.
Click on Places at the top-left corner of your screen. Left click on Windows drive (where Windows OS is installed). You can easily identify this by observing its size.
The correct hard drive will have the WINDOWS folder in it. When you find it, make a note of the drive's label that appears in the menu bar of the file browser.
Now, start a terminal window by going to Applications > Accessories > Terminal.
In the terminal window, enter the commands
sudo chntpw SAM
SAM is the file that contains your Windows registry. You will see some text appear, including a list of all of the users on your system.
At the bottom of the terminal window, you should see a prompt that begins with "User Edit Menu:" and offers four choices. It is suggested to clear the password to blank (because you can always set a new password in Windows once you log in). To do this, enter "1" and then "y" to confirm.
If you would like to reset or change the password of an accout type other than the administrator, just change a line in Step 13, In place of
|sudo chntpw SAM|
|sudo chntpw -u <|