There are plenty of things you can do with an old PC, you could use it as a coffee table, a door stop, or turn it into a powerful firewall to protect your current home or office network.

Routers which contain your firewall are essentially small, slow running PCs. So, if you've got an old PC lying around, why not try this security boosting PC hack.

Dusty old computer

To turn your old PC into a firewall you’ll need the following items at the ready:

  • An old PC tower
  • A monitor
  • An additional network card
  • CD writer (although not essential)
  • ADSL router

How to turn your old PC into a firewall: Upgrade your hardware

To turn your PC into a unit capable of connecting to the internet and running a firewall, you can add an additional network card, or multiple.

Ideally, you’ll want one that provides a couple of ethernet cables and a Wi-Fi card.

How to turn your old PC into a firewall: Download pfSense

pfSense is an open source firewall software distribution based on FreeBSD. To download the software visit and visit the downloads section.

From there click on the latest ISO version. This will run with a CD writer.

pfSense will then offer multiple servers to choose from, so choose the one nearest to your location to access the ISO. Opt for the 32bit version as this will run with as little as 4GB of RAM.

Then download. (For a more detailed tutorial see: Installing pfSense)

How to turn your old PC into a firewall: Burn ISO to a disk

Copyright pfSense

This step is simple, burn the downloaded ISO onto a CD.

If you don’t have a CD writer, here’s how to do it:

Download Rufus.

Rufus is a specialised software that essentially ‘burns’ data onto a USB drive.

How to turn your old PC into a firewall: Bootup the CD

Place the CD in the PC drive and select ‘Default’ from the list of options to boot it up.

Next install pfSense to the hard drive. To do this you’ll need to select this using your keyboard and the corresponding number, it should say something like “Install pfSense to hard drive etc.”

This should start pre-installing pfSense, and the front end install wizard will open.

From there you should opt to keep everything default and accept the settings and choose easy install.This will reboot you PC.

You might want to install a processor to help things speed up.

How to turn your old PC into a firewall: Open browser with IP address

Once the pfSense has been installed, you’ll be given a default address, this can be entered into the browser and this will take you into the pfSense interface.

From there you’ll be able to login to pfSense, but if you don’t have an account you will be asked to provide a host name, domain name and server information.

You should follow the pfSense wizard from here by providing your network information and supplying a secure password.

Alternatively, the username Admin and password pfsense will log you in depending on which version you have downloaded.

Once you’ve provided all relevant network information, the pfSense configuration will be complete, taking you to a dashboard.

You should note that most fields are not compulsory to complete.

How to turn your old PC into a firewall: Connect your router

You’ll now need to place one network cable into your modem and the other into the 'WAN' port of your router.

If you have an ADSL router you'll need another router as this does not require a modem to connect to the internet.

To make your router work with your newly recycled PC and the pfSense software, you’ll need to create a switch, this is an access point and is necessary if your PC doesn’t have Wi-Fi capabilities.

You might have to disable the DHCP server and change the PC address before you connect one of the LAN ports to the LAN of the pfSense server.