Administrator password reset

Hi,

Yesterday, I tried installing Service Pack 1 for Windows 7 Pro on my Vostro 1720 Laptop, but I found out I need to be logged-in as administrator.  Since I never used this "account" since I first installed programs on my machine, I forgot my administrator password.

Is there an "easy" way to recover the password or to change to a new one?

Thanks.

Gilles Paquette