You may have noticed a rather annoying message on your TV screens for the last few weeks getting right in the way of Ian Beale, Holly Willoughby, Jeremy Clarkson and most of the United midfield. If you've taken the time to read the message, rather than scowl at it until it disappears, then you'll have noticed that there's something going down on Wednesday 30 September, and yes, there's a very good chance that it applies to you, so read on for all the info you're going to need.

In a nutshell, the TV broadcasts are upping sticks from where they currently sit in the electro-magentic spectrum and setting up camp elsewhere at another wavelength where there's more room. One of the problems with the current set up is that firstly, there's no extra bandwidth about for the upcoming Freeview HD channels to use - and they're going to use a lot of it - and, secondly, not everyone in the whole country can receive the section that carries Channel Five. So, all of the TV and radio stations are moving to a different wavelength where your digi boxes are not trained to look for them. On 30 September, you'll have to retune your box so that you can find out where they've gone.

The retune will effect 18 million homes in the UK, so chances are, yes. If you use Virgin, Sky or Freesat you don't have to. Satellite and cable services go through those kinds of updates without you having to tell them to all the time, so they'll take care of that one for you. But, if any of your TVs in the house work on Freeview - including Top Up TV and BT Vision - then you will have to retune those sets and DVD/Video recorders.

Freeview is saying to get on the case any time from after lunch on 30 September 2009. The channels might not have all finished their migration before 1pm, so best to leave till after, otherwise you may have to do the whole thing twice. You might see that the the names of the stations are there but it doesn't mean that the actual broadcasts are, so hold off till the afternoon.

Well, every set top box, TV, and recorder is slightly different but the typical scenario goes:

Step 1

- Turn on your TV

Step 2

- Press the Menu button on your remote control

Step 3

- Navigate to the Settings area and then Set Up and Installation

Step 4

- Select the option entitled "Full retune"/"Default settings"/"Factory settings" or a similar choice. It may give you a panic warning like "Do you really want to delete all channels" but there's no need to be alarmed. Just say yes. They'll come back.

Step 5

- Sit back with a cup of tea and wait while your equipment scans the aerial's input and locates the channels for you. You'll most likely see a progress bar letting you know how it's all going.

If your set top box or TV receives the aerial signal through a DVD or video machine, then make sure the recorder is on standby before you start tuning and if you're at any point prompted for a PIN or 4-digit code then try 0000 or 1234.

Your equipment may switch itself off during the process but that's fairly normal, so don't worry. Turn you TV back on and you'll find that all the channels are there including a new one on 38 called Quest. You may also be pleased to see Five if you didn't have it before.

On the downside, there's an excellent chance that all your personal settings will be lost - including your favourite channel selections, whether or not you want subtitles on and the entire order in the onscreen TV Guide will probably have changed too. If you use a Freeview+ recorder, then you might also need to check the future recording settings to make sure your system is scheduled properly to catch your favourite shows.

The other bad news is that in areas where digital switchover has already occurred you will probably lose the Community Channel and 460,000 people in such areas who receive their signal through a relay transmitter will also lose access to ITV3 and ITV4.

Sadly not. There are a few people out there whose equipment will not cope with the retune because they cannot receive certain bandwidths and you will retune to find absolutely zip. Not fun. This is only true if you're using old equipment and many of the manufacturers of that hardware will be offering firmware updates to fix the problem. Unfortunately, some will not. The one's to watch out for are:

Set Top Boxes

Daewoo DS608P - Call 0870 100 25 25
Labgear DTT100 - No longer trading
Triax DVB 2000T - No longer trading
Portland DP100 - Call 0870 100 25 25

Set Top Box/TV combos

Daewoo SV900 - Call 0870 100 25 25
Bush IDVCR01 - 0871 230 177

A small handful of other systems may also have the odd teething problem, such as BBC channels moving up to the 800s, but it's only the ones above that you'll probably have to replace. Not fair, we know, but the good news is that the cheapest Freeview boxes start at £7.

It should all run relatively smoothly and will do for the vast majority of people but there's bound to be a hitch or two somewhere. It'd be difficult for such a big move to go entirely to plan. So, if you find yourself stuck, then the best thing is to call Freeview which has set up a hotline especially to troubleshoot any issues and sort out individual problems. The number is 08701 111 270 and if that's jammed up, then try your hardware manufacturer too. Good luck and see you on the other side.