1. Go to start menu, click to ‘run’ and type ‘cmd’.
2. Once command prompt comes up then type in: ‘net user’. It will list the user names of the computer.
3. You need to type ‘net user username’. So if the username is Jack, you need to type ‘net user jack’.
4. After this you see saying on command prompt “you may change your password”. To change password type all as in step 3 and add password at the end. If you want to add password abcd then type ‘net user jack abcd’. You will successfully change the password.
Try this only for your own. Don’t do it against any other. We know its very painful to see password not working.