My name is Harish and I work for the Social Media and Community Team at Dell
1. Press F8 immediately after you start your computer. When the windows menu comes out, select Safe Mode using your keyboard. When Windows has started into Safe Mode, select Administrator as your account to log in.
After logging in, click on start, click run, and in the prompt that pops up, type "control userpasswords2" (without the quotes). Select your own account, and click on reset password. Type in your new password and restart the computer.
Let me know if this helps or if you need any further support please reply us back.