As I recall this was a symptom of a bad install. I would uninstall, then use a registry cleaner like CCleaner (free download), then reboot and reinstall.
Read the post at the top of the TRS2006 forum about installing SP1 if that is what you want to do. You can NOT start TRS2006 before installing the service pack. In other words, you do a clean install of TRS2006 and then without starting the program you then install the SP1 patch. Failing to follow the instructions will cause the problem with the Drivers being unavailable.