Hello Steve -
Usually we see errors of this kind when the software package is installed by a user other than Administrator on NT machines. Calibration Executive is usually the specialty of the DAQ discussion forums, but one TestStand-related suggestion I can offer you is that (if you have it) you should uninstall TestStand first and then install your Calibration Executive to guarentee that you won't have any class conflicts. Once it is on the machine and responding well, reinstall TestStand.
--Regards,
Elaine R.
National Instruments
http://www.ni.com/support