Joe,
In answer to your questions...
1 ***Would the harddrive not being locked make the xbox not play origional games???***
Answer: No, if you installed a different dashboard, you could still run signed code (original games). All the hard drive locking will do is allow you to boot into your original MS dashboard. If you boot into EvoX, Avalauch, UnleashX, etc. you'll still be able to run your original game discs and whatnot.
2 ***I think I know the password but if its wrong is there any hope???***
Answer: Yes, there is still hope. A smart fellow made a tool that brute forces the ATA password stored on the hard drive. There is a pinned tutorial somewhere in the forums on how to do it. If I come across it I will post it in this topic, otherwise, I would suggest you start browsing the xbox-scene.com tutorials. It's on there somewhere. Good luck.