• The picture shows a phone cable that connects to the back of your computer and feeds the Internet signal into your modem.

Viewers have been writing in to the Watchdog Office after receiving phone bills for over £1000 to premium rate numbers they have never dialled.

A clever bit of software which causes this may slip unnoticed onto your computer via the Internet (unless you have a firewall) or you may be offered this software when you're Internet Surfing as a faster dialler or to speed up your Internet connection. 

Congratulations to NTL who are on the case - one of the few websites which offered details! 

Even if you click the "No" button it will download to your computer.

Instructions for avoiding pop-ups can be found at the bottom of this page or by visiting Judy's pages on the BBCi Radio Solent Web site and clicking on Sheet 91 - you can also download free software to help with this from the NTL Site. (All links are in our RELATED INTERNET LINKS panel)

This is from the NTL website site:

Internet phone dialler fraud (Updated: 5 April) 

Who is affected: All internet users

• ntl would like to warn all customers about the risk of inadvertently loading premium rate phone dialler software onto your computer.
  
• This software could reconfigure your computer to dial a premium rate number to connect you to the internet, or cause your computer to dial other premium rate numbers without your permission, resulting in large phone bills.
  
• This problem mainly affects dial-up internet customers, but can also affect broadband customers if you leave your phone line plugged into your computer.
  
• Whilst there are legitimate uses for dialler software applications, many are designed to be downloaded and installed without your consent and to connect to premium rate telephone services, sometimes costing as much as £1.50 per minute, without your knowledge.

How to tell if you are affected 

• You should thoroughly check your phone bill for any 09 premium rate numbers, and check your dialler settings to make sure there are no unrecognised dial-ups set up.
  
• These can be found by going into Internet Options on your Control Panel, and clicking on the "Connections" tab or by searching for "Dial-up Networking" in Windows Help.

What should you do? 

• Installing and configuring a reputable firewall application will protect your PC from unauthorised downloads, and give you an opportunity to block any attempted downloads from unrecognised sources.
  
• You can download a free firewall here
  
• You should not download software from the internet unless you are sure of the source.
  
• It is your responsibility to make sure your computer is not used to make these unauthorised premium rate calls, and as an ntl telephone customer, you can bar premium rate phone calls from your line.
  
• Other telephone service providers can also offer this service.
  
• If you suspect that you have been the victim of such a fraud, contact ICSTIS, the body that supervises telephone information services such as premium rate services, who can investigate cases of telephone fraud.
  
• If you are an ntl broadband customer and you also have a conventional modem in your PC, we advise you to physically unplug your modem lead from the wall socket.

Pop up box information taken from Judy Goodlet's Fact Sheet number 91:

Here's one way to stopping some of those irritating pop up adverts on the Internet (sorry, you need Windows 2000 or Windows XP for this).

Messaging within Windows was developed for IT administrators to send messages around the network - but cunning programmers have exploited the Messaging system to launch the pop-ups.  To turn off the Messaging feature:

Judy Goodlet

• Get the latest IT tips every Tuesday morning on BBC Radio Solent from Judy Goodlet.