Neo 4 port

Can I use 2 digi neo 4port cards in the same computer running windows server 2003?

Yes, you can install multiple Digi Neo adapters in the same PC. Up to 4 are tested in a single PC.
Windows will likely install older drivers.
You may want to obtain and install the latest drivers from our web site:
http://www.digi.com/support/productdetl.jsp?pid=1878&osvid=58&tp=1&s=30