Hi Mikirius,
Thanks your help. I think I have found where the root cause is!
The NI488-2 I used to do applicatoin desing & implement now is 2.7.3, but the one installed in "problemed" NB is older than 2.7.3!
So it seems that development environment (eg. DLL or ...) in both systems are not the same and incompatible.
Yesterday, I uninstalled the older one and install the new one currently I used, and then my program works!
Sorry for you spent so much time to support & analyze.
Thanks again for your help...