Does the preview work?

No, the preview doesn't pop up.  The sales order just closes as if we've just clicked on accept.

Things I would do:

1. Check the printers listed on work station. Make sure all actually exist on the network. No local printers. 

2. Have someone else log onto Sage 100 and try to print

3. Switch users on work station and start Sage 100 and try to print.

4. Check Windows Firewall and Anti-Virus settings.

All other workstations can print the sales orders when clicking "Print Order", but at that particular work station even switching users, it doesn't work. It just closes the order. As for checking the firewall & anti-virus settings, I'll have to get my Sage partner to do that as they are our IT experts. Thanks so much for the reply. I was hoping it was something simple, but it seems to be beyond my knowledge. 

The windows login used for the workstation install may not have been a local Administrator.  Log on to the machine with an Admin login and reinstall / repair.