Farmertom,
This error is saying that something in your Registry dealing with the Installsheild program has been coruppted. You can fix this by reformatting the computer as this guy did:
http://forum.mtu.com/showthread.php?...ight=Error1612
Or if you know how to go into the registry, you can search through it and try to remove everything dealing with Microstudio. THis has worked for one other client that knew how to do it, if you don't then you will not want to try this, because if you delete the wrong thing, it could shut the computer down.