As I said in my previous message. I am unable to Erase All Content and Settings. When I try to, it freezes and I have to do a hard reset to turn it back on. Then when it comes back on, nothing is erased.
Well, I have never heard of "Erase All Contents & Settings" not rendering a jailbroken iPad inoperable, which is what you are trying to do. For the avoidance of doubt, that is the ONLY reason I am recommending you do this. Normally you NEVER take this option with a jailbroken device, but you have stated you want to return the device to Apple and it is jailbroken, but you can't restore it on the computer.
Usually, once you press the "erase all content and settings" button, the device should be stuck at the Apple logo and even if you reset the iPad it should still hang there in an endless loop. I am amazed you are able to reset and get the iPad to reboot into a jailbroken state. How long did you leave it stuck at the Apple logo before you reset? You should leave it for a good few minutes, and not reset immediately. Perhaps it is because you tried to remove components of the jailbreak with Mobiile Terminal, I don't know and it is impossible to troubleshoot.
The only option open to you now is therefore to fix the problem with your PC. You need to put your device back into DFU Mode and then get the drivers to install correctly. You must have interrupted the process before (it is easily done).
The easiest way to do this is to plug the iPad into a DIFFERENT USB port than the one you are using ONCE the iPad is in DFU mode (not before). You know it is in DFU mode if you followed the instructions and the screen is black.
If you are using a USB hub, then don't plug it in there. Plug it directly into another main USB socket on the computer and allow the DFU driver installation to complete. iTunes should then recognise the device and allow you to restore it to factory settings.
If you cannot solve the problem with your PC, then you will need to try any friends that has iTunes installed (it will not mess up their PC, as long as you connect the device when it is in DFU mode and allow the drivers to install). Again, iTunes will prompt you to restore the iPad and it will set it back to factory defaults on 4.3.3.
Sorry I can't be of any more help.