There is no connection to the server. PostgreSQL?

Question

PostgreSQL

Good day everyone! I am making a network in the office, as planned, there should be a server (a regular computer on windows 7 32bit) with computers connected to it (windows 7 32bit). A corporate program for working with the database is installed on the server, as well as the database itself. From computers, you need to go to the server and install a shortcut to this program so that you can work from the workstation. The problem is that when I try to select a database to work from a workstation, I get the following error:
“There is no connection to the server!
couldn't connect to server: Connection timed out
(0x0000274C/100060)
Is the server running on host “192.168.1.100” and accepting TCP/IP connections on port 5432?”
For some reason, Habr cannot upload a photo, so I write in words)
At attempt of a choice of a DB from the server of such problem does not arise. Ping on the command line also works. Thanks in advance:)

Answer 1

“192.168.1.100” and accepting TCP/IP connections on port 5432?
if you execute the command telnet 192.168.1.100 5432, what happens?

Answer 2

Understand the difference between a local connection and a connection to the DBMS over the network, which configuration files are responsible for this, whether any firewalls are configured, etc.
Standard diagnostics, in general.