Printer shows offline

We recently attended a printing problem of a customer using a Windows 10 laptop at home. The laptop was connected by Wi-Fi but had repeated trouble printing to their Wi-Fi connected Printer.
Sometimes this can happen if the Printer is far away from the Wi-Fi router and the signal at the Printer’s location was very low or being blocked by interference from other equipment in the home.
However this was not the case as the printer was only one metre away. Her computers in the home was able to print wirelessly to this printer with ease.

She had already uninstalled and reinstalled the Printer drivers numerous times, to try to resolve the problem. This would resolve the problem for a few days however the problem would soon return.

Looking at the Printer in the “Printers and Scanners” setting, showed that the printer was “Offline”.
This is why the laptop could not communicate with the printer and therefore, unable to Print any documents. In the reverse, the customer was unable to scan any documents. In other words the Printer was completly unusable to her in this state of affairs. This unacceptible situation was causing our customer great anxiety, as she had to urgently print some documents, in order to be able to sign them and then scan them to email them to the government.

Going into the “Network & Internet settings” showed that the laptop had marked her home Wi-Fi as a Public location.

In our customer’s case, she had visited a friend in another state and joined her laptop to their home Wi-Fi.
When you join your computer to a foreign network connection, Windows gives you a pop up that it has detected a new network and asks if this is a trusted network; if you need to share files etc. If you answer “No” to this question, then Windows changes your laptop’s Firewall to the much more restricted Public setting.

This causes the Windows Firewall to be switched to a much more stricter state as this setting is for when you are joined to a Public Wi-Fi network. Many of the data signals that flow into and out of the laptop are severly restricted to protect the user; including the bi-directonal heartbeat signal that constantly connects the laptop to the Printer and allows you to print or scan a document as you require.
After changing the network for a Public to a Private trusted network, the Printer sprang to life.
Only use the Public network setting if indeed you are connected to a foreign Wi-Fi network such as at an Airport, Coffee Shop etc.

If you have joined a foreign network, then you just need to remember to change this setting back to Private when you return home, otherwise you will have problems if you need to use your home Printer as was in this case, or if you share your files on your home network.