Here is a simple tutorial on resetting the admin account password of any WindowsOperating System. All you will require for this is one Ubuntu live CD.

1. Insert Ubuntu Live CD and boot from it.
2. Open terminal and install chntpw in Ubuntu. To do so use the following commands.
   sudo apt-get update
   sudo apt-get install chntpw
3. Now mount your Windows volume. In my case it was dev/sda1. Replace it with yours.
   sudo mkdir /media/WINDOWS
   sudo mount /dev/sda1 /media/WINDOWS
4. Now navigate to the Windows configuration folder.
   cd /media/WINDOWS/WINDOWS/system32/config/
5. To reset the administrator password enter
   sudo chntpw SAM
6. After completing this command you will see 5 different choices. Select the 1st one and press Enter and done
7.