Well, if you never actively disabled it, then it should, in theory, still be on, unless you have to re-enable it on the stock ROM each time you plug in.
Anyway, here goes, hopefully it works. Turn the phone on, plug into your PC.
Go here:
androidscreencast - Desktop app to control an android device remotely - Google Project Hosting
Follow the installation instructions. They are VERY simple. You should be able to run this program, and see your screen on the PC, control it with your mouse / keyboard, etc...
If that works, go into About Phone under your settings, and tell me the exact version of Android you are running. That will tell us if you have a new or an old screen. 99% sure you have the old one, but I could be wrong, I don't know exactly when the switch happened.
If you're running 2.2.2, you'll now want to go through and back up anything you want to keep to your SD card. You can use SMS Backup & Restore in Play to backup your texts, and Titanium Backup to backup app data that you'd like to keep.
If you're running 2.2.3, we can go through installing a custom recovery and making a nandroid backup for you to just restore on the new device.