To detect a firewall, check to see if any applications within the system tray could be a firewall. Alternatively, find firewalls by performing a system evaluation on the running programs.
To check the system tray, hover over icons to see the name of each application and see if they are familiar. If an application or program is questionable, search the program's purpose online. Do this until an application is found that represents a firewall.
Another option is to view all running programs on the computer and figure out which is a firewall by pressing the Control, Alt and Delete keys simultaneously to access the Windows Task Manager. Under the Processes tab, and evaluate the list of processes that are running. Firewalls are very likely to be listed, especially if there is more than one firewall running on the computer.
To see if the firewall is turned on in Windows, click the Start menu, and type "windows firewall" within the search box; select the "Windows Firewall" option. If the Firewall is turned on, a Turn Off Windows Firewall option is available under Home or Work Network Location Settings. If the settings haven't been altered yet, a Turn Windows Firewall On or Off option is listed.
On a Mac, go to System Preferences, and select Security; go to the Firewall button. Locate the padlock icon at the bottom, and enter the user's password. If the Stop button is shown, the firewall is turned on. If a Start button is available instead, the firewall is turned off.