In the days before online catch-up TV service, such as the BBC iPlayer, stopping children watching unsuitable content was fairly easy, parents could simply switch off the TV if they didn't think the broadcast was appropriate, or even simply ensure children didn't watch programmes shown after the 9pm watershed.

Now however, with online TV services readily available, kids can access TV shows shown well after the watershed from their PC at any time of the day. Ideally, parents should be monitoring their kid's online activities, but if its not always possible to keep an eye on your children when they're surfing the web, what can you do? This is where the Parental Guidance Lock feature on the BBC iPlayer comes in. Once the function has been enabled, anyone using the PC will have to enter a password before they can play a guidance-labelled programme on the catch-up TV service.

The BBC says guidance-labelled programmes, which are marked with a red and white G icon, feature unsuitable content such as violence, sex, drug use or strong language, as well as videos that may be harmful to view because they contain flashing images. Furthermore, the majority of guidance-labelled shows were initially broadcast after the Watershed.

Here's how to activate and use the Parental Guidance Lock.

Step one
Open the BBC iPlayer and select a programme that is guidance-labelled (most broadcast after 9pm fall into this bracket).

Step two
Click on the padlock icon to the right of the guidance label. You'll be redirected to the Parental Guidance Lock homepage.

Step three
Here you'll be asked to confirm you're over 16 and then required to enter a password and email address. The BBC says it only requires an email address so your password can be sent to you should you forget it. Press Ok.

Step four
Now as soon as anyone uses that PC to try and view guidance-labelled content, they'll be asked to enter the password before they can proceed.

Step five
To remove the Parental Guidance Lock, simply click the Parental Guidance link which appears on the bottom right of all iPlayer pages. Then select the link which says Click here to turn the Parental Guidance Lock off. You'll be asked to enter your password before the lock is removed from the PC.