I bought a MBP used off eBay. The previous user tells me he deleted the admin account and only left guest access enabled. That seems to be the case, as far as I can tell. He did send me the username and password, which I tried to use to unlock the user accounts and add a new user, but no luck. I can only see the guest account when I restart the computer, with no option for admin login. Suggestions? I'm on OSX 10.7.4 (still have my old snow leopard discs but he didn't include the new discs for this machine). I could just drop a new, larger hard drive in, and reinstall OSX but I'd rather not open it unless I have to. Thanks IN ADVANCE for any help!