Q: When I left the Island for a few days, my computer's desktop etc. was blue, like it was when I purchased my Dell computer with Windows XP less than two years ago. When I returned, the colour scheme had changed from blue to green. I can live with that except that all the faces and skin tones of people in my photograph files are now bluey purple. Someone said the problem might be that my monitor has worn out. Already? I have never had such a problem before or any indication of colours changing. My monitor came with the computer. It is a 15-inch colour multi-scan KDS monitor.

I've been into the Control panel to Display settings to try and change it back but have had no luck. Any idea what could have happened?

A: Certainly a healthy computer should not spontaneously change its colour scheme. I see you write that the faces and skin tones of people are now bluey purple. Unless you only take mug shots of hockey players I think there for can be little doubt that you are experiencing some form of hardware failure.

The hardware components that produce the video picture in your computer consist of mainly two components, one is the video card which is a PCI or more likely an AGP graphics card attached to your motherboard. If the graphics hardware is built-in the video information originates from an area of circuitry integrated into the motherboard itself. The other major hardware component is the monitor itself which, I think in your case may be the culprit, although KDS is a good enough aftermarket Korean brand.

Assuming you don't have another computer with a monitor in your house, the obvious thing to do would be to borrow somebody else's analogue monitor and attach it to your computer and see if your colour is restored to what it should be. If you can do this make sure the computer is turned off before you change monitors. After attaching the borrowed monitor, turn the computer back on, with your XP operating system, it ought to tell you that new hardware, that's the monitor, has been found. Just let this process continue until use see a notification that your new hardware is functioning or until it is obvious from looking at the screen that your new monitor is working properly.

Perhaps your monitor has been effected by a power surge or lightning or by some internal faulty component. CRT monitors don't last forever although two years is about half the life that I would have expected from one. LCD monitors (the modern narrow ones) are supposed to wear out even sooner. I find that the bigger the screen size on the monitor the less time it lasts, probably as a result heat generated by the big monitors.

I don't expect a monitor to produce true blacks and brightness after about three years of being on constantly. On the other hand some technicians argue that the turning off and on computer components is what wears them out because of the repeated expansion and contraction as the components heat up and cool down.

A quick look on the Internet shows that even at local prices 15-inch CRT monitors are available for $173, and 19-inch monitors, which are much kinder to your eyes, for $199.

If you try swapping monitors and you still have the problem of the distorted colours you should write and let me know. At that point a technician, would need to see both the monitor and the computer to try to determine what is wrong. I hope it doesn't come to that.

Q: I saw in another column you wrote that Windows XP has its own firewall called Internet Connection Firewall. Yet you seemed to be also advocating acquiring another one too. I have Norton Personal Firewall. I know you mentioned it, but is it any good? Do you suggest any others? Since XP already has its own firewall, is it smart to switch them both on?

A: Some tech people consider XP's integrated firewall (ICF) to be weak and inflexible, and recommend the use of a third party firewall. However, it is free and it is already in place with XP. The biggest problem with XP firewall is that it only blocks incoming signals, not outgoing ones. This is the way Microsoft designed it, however, it makes ICF useless against Trojans and other malicious applications that "phone home".

Microsoft ICF also can prevent certain freedom of access when it comes to file-sharing between PC's. Users sharing a home-office with a simple network sometimes turn the ICF off to make life easier.

Also, ICF won't tell you at the time of an attempted intrusion. When the Norton Personal Firewall on my own PC catches an intrusion attempt it tell me instantly and that is reassuring.

When a customer wants me to install a separate distinct firewall on their computer I generally use Norton Personal Firewall because of its ease of configuration and ready availability locally. However, Sygate, which is considered by many as an excellent choice, claims that their Personal Firewall PRO is the first that integrates meaningful operating system layer protection, guarding the legitimacy of outbound traffic.

The Sygate Personal Firewall PRO blocks any traffic generated before its own service starts up, eliminating the brief security policy vacuum. Also it claims to automatically terminate known attacks such as Trojans, Denial of Service (DoS) Zombies. It also has defense mechanisms that prevent malicious code/and or users from disabling or exiting the personal firewall.

If you want to test the vulnerability of your computer system to invasion, both from a security hacker standpoint as well as from attack by the latest viruses go to http://security.symantec.com/sscv6/home.asp? and run through the two online checks freely available there.

If you want to compare the leading products here are some sites to look at.

Norton Internet Security 2003

http://www.symantec.com.au/sabu/nis/nis_pe/; Sygate http://smb.sygate.com/; ZoneAlarm http://www.zonelabs.com/store/content/home.jsp

James W. Lapsley of ComputerWorks, specializes in PC repairs, upgrades and advice for the home and small office user. ComputerWorks welcomes your questions and comments Send your PC questions by e-mail to computerworks@logic.bm