How to "Delete Administrator Password" without any software

Method 1

Boot up with DOS and delete the sam.exe and sam.log files from
C:\Windows\system32\config
in your hard drive.

Now when you boot up in NT the password on your built-in administrator account which will be blank (i.e No password). This solution works only if your hard drive is FAT kind.

Method 2

Put your hard disk of your computer in any other pc.

Boot that computer and use your hard disk as a secondary hard disk (Don't boot as primary
hard disk ).

Then open that drive in which the victim’s window (or your window) is installed.

Go to location
C:\Windows\system32\config

Delete SAM.exe and SAM.log

Now remove hard disk and put in your computer.

Now boot your computer.