Q: I would really like to buy a flat-screen monitor and they do seem to have come down in price recently. What things should I be looking for in a good flat-screen monitor?

A: Iiyama have bought out a new range of monitors based around thin film transistor (TFT) technology, often used in notebook displays. You can now buy a 15-inch, flat-screen monitor for £433, incuding VAT and a 17-inch version for £809. See www.scan.co.uk for more details.

There are a couple of things you need to look out for. The first, and possibly most important, is the refresh rate. This should be no less than 72Hz; any less and the screen shimmers and can cause eyestrain and headaches with prolonged use. You should also consider the viewing angle of the screen; many flat-screen monitors only have a clear and bright display when viewed from a particular angle.

Finally, you should consider what the maximum resolution of the screen is. Ideally it should be able to display a resolution of 1,024 by 768 by 24 bits (millions of colours).

Q: I sent a short video clip to a friend of mine but, when he tried to play it, an error was displayed saying it wasn't a valid AVI file. Yet it plays fine on my machine. Why is this?

A: Your problem probably stems from the codec (the type of compression) used on the video clip. There are a number of codecs (short for encode/decode) available but not all of them can be installed with a basic Windows installation. It is likely that you compressed the video using a codec that is not installed on your friends machine. To resolve the problem, try compressing the AVI using a common codec such as Video 1 that is supported under all versions of Windows.

Q: I am thinking about buying a new motherboard for my computer and was tempted to buy a dual processor board. Are they much faster than single processor boards?

A: You are right to be cautious. Although common sense would argue that two processors are better than one, unless the software you are using is specially written to take advantage of a multiple processor motherboard, you may not notice the kind of speed improvement you would expect. The other thing to bear in mind is that your PC is only as fast as its slowest component, usually the hard disc, so your extra powerful motherboard could be spending most of its time waiting for something to load from the hard drive. Basically it comes down to what you use your PC for. If you use it for 3D rendering or other intensive computational activity it is likely the investment is worthwhile. Otherwise you may be better spending the money on a faster single processor system.