Forgetting Windows password is the most annoying thing. Not only because you know you can reset your Windows password and recover access but also because you are going to need another pc to burn a Linux live CD / USB drive (if you don’t have one).
Before you start with the procedure you need to prepare a bootable CD/DVD or USB thumb / flash drive.
Download the linux live CD image like Ubuntu for example, from here http://www.ubuntu.com/download
Burn it to your USB with this tool http://unetbootin.github.io/ (WARNING: All the contents of your flash drive will be lost!)
Or to a CD with this tool http://www.imgburn.com/
Remember we need another pc to complete the above procedure OR if it happens to have one around just a Linux live CD / USB
After burning it
Insert the USB / CD / DVD to your pc, and at the POST which is the power-on self-test and checks a computer’s internal hardware for compatibility and connection before continuing the boot process, press the key to go into the boot menu
Usually it is F8 or F10 or F2. Press it numerous times until the boot menu comes up.
Select your drive you’ve just inserted from the boot menu, so it can boot.
After booting the Linux
First we need to mount the Windows partition.
Open the File manager from the menu (usually it’s a folder icon).
In the right will be a devices section listing all partitions with their size that exist in your system.
If you don’t remember what size is the partition where the Windows is located, don’t worry.
Click on every partition until you find the one with the windows files. Obviously it has to contain a folder named “windows”.
After that unmount all the other partitions, by right clicking and “Unmount”.
Then open up a terminal (usually opens with CTRL + ALT + T but if not you can find it in the application menu)
To install chntpw (Change NT Password software) type (in debian based distros):
sudo apt-get install chntpw
which will install the software which resets your windows password.
Don’t worry all live Linux software installations are happening to a temporary disk drive, so you will not mess with your existing Windows setup.
After installing chntpw
Switch to the Windows directory where the passwords are located, by typing
cd /your/path/to_the_windows_partition/Windows/System32/config
And then run it by typing
sudo chntpw SAM
You should now see the chntpw screen. Here you have five options:
- Clear user password
- Edit user password
- Promote user (make user an administrator)
- Unlock and enable user account
- Quit
Select 1 (Clear user password) and then type y to confirm
This will reset all your windows passwords. You can set new passwords from inside Windows afterwards. And you are done! You have reset your Windows password successfully.
Restart and you are ready to go. Your password has been removed and you can set a new one.
chntpw is an open source utility which has saved me lots of times. Now you know how easy it is to reset your Windows password, it may make you think twice about how secure the Windows login system is.
Photo by Luke Higgott 
