I bought a used computer that the seller no longer used because they couldn't remember their local account login password. I thought it would be an easy fix to use command prompt and change the admin password that way. But when I get the screen that gives me the options to load Safe mode, safe mode with networking, and safe mode with command prompt, regardless which of the options I choose, it just loads to the normal log in screen. I do not get any kind of screen or box to enter commands. It's a Lenovo laptop running windows 7 home premium. Can someone please give me a idiots step by step rundown how to fix this?