This is where you find them:
http://www.mtu.com/upgrades/hoster/v...de-hoster4.htm
This is for Hoster 4 but can't hurt to do them for 3.321 either and then you are ready for 4 when you want to upgrade.
When you re-loaded your computer did the external drive come up with a different drive letter from what you were previously using?
Is the list of folders in the rebuild screen showing the correct drive and folder or does it list C:\MTU\KMA Files?
When you reloaded Windows all your registry entries are wiped out and so Hoster resets to default locations.