A firewall is a protective system, either software or hardware, which protects your computer from unauthorised access.
It is actually more like a door between you and the internet, and controls who is allowed to access the information you hold on your machine.
It can also control when programs on your computer are allowed to access the internet and should notify you if your machine is trying to access the internet in a suspicious manner.
Does my computer have a firewall?
If your computer is running Windows XP with Service Pack 2, Windows Vista, Windows 7 or Mac OS X – it has a firewall. For most other systems, you need to install a separate firewall.
I’ve got a firewall. Am I okay?
No. You need to be sure that your firewall is turned on whenever you are accessing the internet. Simply having a firewall installed won’t protect you.
Do I need to turn the firewall off to do some things on the net?
Never turn off the firewall if you are connected to the internet. Some software will conflict with the firewall at first but these conflicts can be resolved without turning the firewall off.
My firewall is asking me to let a programme access the internet, what should I do?
If you recognise the programme that is requesting access, you should be okay to allow it. If in doubt, don’t.
My computer doesn’t have a firewall – help!
Microsoft users can install Security Essentials and a scan will detect if you have no firewall active on the PC – you’ll be given the option of turning on Windows Firewall.
- Windows 7: learn more about Windows Firewall
- Windows Vista: review Microsoft’s Security and Safety information
- Windows XP: how to protect your PC
- Mac OS X: protecting your computer with a firewall
- Watch our NetBasics animated episodes to learn how a firewall can keep you secure: