Assuming you are using Windows Firewall . . . and you have sufficient administrative rights to alter the settings (e.g. not being controlled by domain group policy settings)
Start => Control Panel => Windows Firewall => Advanced Settings => Inbound Rules => New Rule => Port => Next . . .
And look in the list for any rules that could be blocking the connection.
Do you mean TCP or UDP port?
What service are you expecting to run on it? Port 1500 is a 'User Port' assigned by IANA using the "Expert Review" process, as per [RFC6335] - listed as "VLSI License Manager" - see http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
Hope this helps.