I want to thank you all for the warm welcome.
Jimbuna, the link you supplied @
http://www.dll-files.com/dllindex/dll-files.shtml?d3d9 was very helpful. It shows the DLL supplied by Ubi is not compatible with Vista.
So I went to M$ help & support looking for a solution.

Then I went to M$ technet. After much reading, I came away with the knowledge that they are the only ones who believe in DX9s' compatibiltiy with DX10. And any question about Vista immediately produced a thread for Win 7.


At least I can still enjoy the game on the other computer. They can't interfere with that. Thanks m8 for your assistance.