When starting a recording in Camtasia Recorder you an an "Unknown Error".
-make sure CamtasiaStudio.exe and CamRecorder.exe are not running
-click Start and type regedit. Hit enter to open the registry editor.
-browse to HKEY_CURRENT_USER\Software\TechSmith\Camtasia Studio\9.0 and delete the 9.0 folder.
-try restarting Camtasia and see what happens