Google launched a new campaign with the Citizens Advice Bureau this week in a bid to promote online safety to Brits. The Good to Know campaign offers advice hopes to encourage UK web users to take steps to ensure they're more secure when surfing the web.

Among the nuggets of advice on the Good to Know website was where possible use two-step authentication, that sees users entering a password then a unique verification code that has been sent to their own personal device such as a mobile phone. Social networking site Facebook is among the website currently offering this secure log-in feature. Here's how to switch it on.

Step one
Start by logging in to Facebook and select Account settings from the drop down menu located next to Home in the top right-hand corner of the window.

Step two
From the options on the left-hand side select Security and then press Edit next to Login approvals.

Step three
Tick the box next to Require me to enter a security code each time an unrecognised computer or device tries to access my account. A pop-up that asks you to set-up the service will be displayed. Press Set-up now.

Step four
Assuming you have already registered your mobile number with Facebook, the social network will send a text with a code you'll be required to enter. Once the code arrives, input this in the pop-up that is displayed. Alternatively, you can change the phone number the text is sent to by pressing Change my phone in the bottom left-hand corner of the pop-up and following the on-screen instructions.

Step five
Once you've entered the code, press Submit code. You'll now be asked to give the computer or device you're accessing Facebook from a name, then press Next. Now every time you access Facebook from any other device, you'll receive a text to your mobile phone with a security code, which you'll need to enter before you can access your profile.

Step six
Facebook will also notify when you use an unrecognised device to log-in to your account through your notifications and you'll be asked to confirm whether it was you or not. If you confirm it was, you'll be given the option to name it, making it a recognised device and ensuring you won't be asked for a security code when accessing Facebook from the device. However, press Don't Save it you want the two-step authentication to remain in place when using Facebook from the device. It's worth noting you'll have to have a minimum of one recognised device to use this service, although that can be your PC.