Why does the password reset disk not work on my windows 7 laptop?

I changed the password to my laptop and do not remember it. So I inserted a flash drive to my friends desktop to make a password resetter disk. Afetr that I plug it into my laptop and click reset password, It asks for the name of the drive i click on the name, after this it asks for a new password and then again for confirmation and password hint. Then when i click finish it says "An error occured while the wizard was attempting to set the password for this user account." What do i need to do to make it work, and can i bring it to radioshack or somthin?