◘Under this section double click on Computer Management.
◘Select System Tools from right window pane.
◘Under this, just double click on Local Users and Groups and then on Users
Now you will see all the login accounts of your computer. Right click on any the account whose password you want to change and then click on Set Password.
◘A warning message will popup on your screen just click on Proceed button.
◘Now enter your New Password and click on OK button.
◘That’s it! your windows 7 password is changed without knowing current password. The only limitation of this method is that your current account should have Administrative privileges.