Q: I am a freelance graphic designer working in the Brighton area. I use computers all of the time. Will I have to buy all new software if I move over to using Mac OS X?

A: If you are a graphic designer, you probably use Adobe Photoshop, Quark for desktop publishing and an assortment of other packages are all worth about as much as your computer is.

ou are obviously a Mac user, running your applications with MacOS 9. The answer is you will have to purchase new versions of these software packages. If you were thinking of upgrading your Mac, then I would do it now. Currently all new Macs are sold with MacOS X and a MacOS 9 compatibility mode.

Soon, all new Macs will be sold with MacOS X only. If you upgrade now, you can carry on using your current software (e.g. Photoshop 6) using the compatibility mode and only upgrade when a new version of the software comes out and when you would have upgraded anyway - this should spread the cost for you.

Q: I am about to buy a new computer. Should I buy one with a flat screen?

A: This is a matter of personal choice. Since I started using a laptop a lot, I have become a real fan of the flat screen but there are several negative points to them too. Flat screens are more expensive and smaller. They are not so good at dealing with multiple screen resolutions, they work best with the screen resolution that they were designed for. And they can be difficult to see from an angle, so are best for just one person to work at. But they don't flicker at all, take up much less desk space and can be easily moved from place to place. In the end, you will need to weigh up the pros and cons that are relevant to you.

Q: I have got a Mac computer. Is there any way I can run software that is only available for the PC?

A: There is software that emulates the PC called Virtual PC. Emulation means your Mac has to simulate all of the functions of the PC when it is running the software. You could con tact your local Apple dealer who would sell you a copy for just under £200. However, a word or warning: Not all PC applications work with the software and others will run quite slowly.

Q: My computer has started to make whining and squeaking noises. I'm worried about switching it on again in case it blows up.

A:The noise is almost certainly caused by one of the fans in the computer failing. This often happens when the machine is about three or four years old. There are two fans in a computer, one is at the back to cool the power supply and the computer in general - you can usually feel the flow of air from a circular vent at the rear of the machine. If it seems that the noise is coming from here, repair should cost about £50. If the noise seems to be coming from inside the little grey box, then the problem is the CPU fan. This should cost less to replace, maybe £20. Either way, it's best to get the problem fixed and not to use the machine too much until then.