Vlad and Erik,
Thanks for the response. I had a prg to make the connection. Before I created the DSN, I ran the prg and got error. After the DSN been created, I ran the prg and worked fine. Then I removed the DSN, and ran the prg again, and it worked too. And my second question: Can two machine make the same connection at the same time by the same UserID and Password? TIA.

Wan