osvaldo, this one coming to you directly from [http://answers.microsoft.com/en-us/windows/forum/windows_7-security/i-forgot-my-password-for-windows-7-for-my-laptop/d3bb29fc-6533-4887-b266-604af142b8e2|Microsoft] " Welcome to Microsoft Answers Community.
You cannot reset it directly as a reset way function. However, you can
remove that password and type a new one instead, by following the steps
here -> Restart your PC, and hold the F8 keyboard button and as You
enter the Windows® Boot Menu you will see some different choices,
choose Safe Mode with Networking. Now Windows® will start in Safe Mode.
Select the default Administrator account from the login, the password
can be blank. If you are lucky and passed the login, then you’re able to
edit your original account." I hope this will help you out. Good Luck.