powerclown

It seems the guest that I let into my house has hacked into my Windows XP Home laptop.

I had a windows login set up (buttons) with an administrator and password (me) and Guest access enabled for him to have internet access.

He has somehow bypassed the original administration/password login and created a new administrator and password. When I asked him about it, he took quite some pride in his accomplishment.

I took a look around the laptop and there are a few things of note. Control Panels now has a file named Borland Administrator something or other that he put there. He has registry backup files (around 8 or 9 files) in a separate folder. I haven't had a chance to check for any hidden files yet. I have a Mac G4, and he mentioned in passing the other day how Macs don't have registries. I believe he has done something through the XP registry, but I don't know what or how.

Does anyone have any idea how he has managed to bypass the former administrator and password and create his own? I have a desktop pc that I'm sure he would be eager to "inspect" as well. Anyone have any ideas as to how to further secure my computer? I know next to nothing about Windows XP security. He seems to have bypassed my first line of defense though.

Thanks...