Reset Windows 7 password without third party tool.

Its nice trick to reset windows password. If you do not have any third party tool. On follwing OS you can apply this method
Windows 7
Windows Server 8
Windows Vista

You need Windows Installation Disc for this. Insert your Windows Installation disk into DVD Drive/CD rom. Change the Boot settings from BIOS.  1st boot device should be DVD or CD drive.

1. Choose "repair your computer" option.

2. Command prompt option from bottom.

 3. By deafult , you will see X:\Sources>   this is your DVD drive.
Try to search Windows folder that will be  original C drive. See the image
go to C:\Windows\System32 and type following commands
ren utilman.exe utilman.exe.bak
ren cmd.exe utilman.exe
restart pc.
See the commands here in image

After this restart you pc. then go to login prompt. Then click on "Ease of Access" Button below at left side. or press windows key + U key together. command prompt will open then type the following command to set the password
net user administrator *  or net user administrator newpassword
to see the all users on computer then type only net user.

Finished.