Unlike Pro Tools LE, Pro Tools 9 does not include the driver installer for your hardware so they will need to be installed and updated separately. Its likely that the previous drivers are still installed even if you have removed them from add/remove programs.
This is the best way to completely remove any old remnants of your previous version of Pro Tools, this also works for having to reinstall Pro Tools 9.
1. Go to Start> Control Panel> Programs and Features
2. Unplug your Avid or Digidesign hardware and Uninstall everything Avid and Digidesign.
3. Once everything is removed plug in your Digidesign or Avid hardware. Go to Device Manager in Windows, then Sound, Video, and Game controllers and check if your hardware is still in that list. If it is then right click on it, choose Uninstall and put a check in the box to Delete Driver Software.
4. Power off or unplug the audio hardware then plug it back in again.
5. If it still shows up under Sound, Video, and Game controllers then repeat step 3 & 4 until it is no longer in Sound, Video and Game Controllers and only shows up with yellow question marks under Other Devices. This ensures that there aren’t any previous existing drivers on your system.
6. Install the new drivers for your audio hardware here: http://avid.custkb.com/avid/app/selfservice/search.jsp?DocId=379411
7. After the drivers are installed, verify that the audio hardware shows up again under sound, video, and game controllers.
8. Reinstall Pro Tools 9.