Well it's up to you how you want to proceed.
Can either try to reset the password for Admin account using a reset disc or just reformat the laptop and install Windows fresh.
If you want to try and reset the password, download this: Offline Windows Password & Registry Editor
and burn the ISO to a CD. Boot off of it, and follow this guide: How To Remove Passwords Using Offline NT Password & Registry Editor
In that guide, on step 11, you'll be able to see what the local Admin account name is. Take note of it when you blank out the password.
If you just want to reformat...then get the ISO for Win7 Pro x64 from the link I posted previously.