I installed Megastor USB 2.0 Mad Dog Multimedia on my laptop, it worked fine, but know my drive is no longer visible, so I can't burn dvd's.
Have you tried to reinstall your device drivers? 1) Uninstall the drivers for this device in the device manager (Right-click on "My Computer" --> Properties --> Hardware --> Device Manager, and uninstall driver for just this device from there). 2) Unplug your USB DVD writer from your computer. 3) Shut down your computer and restart windows. 4) Boot it back up, and once you're all loaded up, plug back in your USB DVD writer. 5) If Windows doesn't automatically find the drivers for the DVD writer when you plug it back in, insert the installation disk that came with the DVD writer and install the drivers for it from there. At least that's a place to start!
you could have a registry mess. Norton system works has a cleaner but I personally recommend "windows registry repair pro," if you download the trialware and upgrade from there it's only ten bucks right now. You might also try avoiding plugging into a hub and straight into the back of the system, some devices don't like to be on hubs.