Since starting Computers for Earthlings, I have received a lot of questions. Here are the answers to three recent ones.

Firstly, it?s worth understanding what job a screen-saver does: If we leave a monitor switched on and connected to our computer, the image presented, if left long enough, will ?burn onto the screen?. It will leave a ?ghost? of the image forever etched on the screen. Thus, in the early 1990s, screen-savers were written ? programmes which will detect inactivity and render a selection of images, or animations, periodically to change the display, thus saving the screen from being damaged as before.

The issue is that such a program must always be running, in order to detect inactivity. Thus, if the screen-saver program is poorly written by the programmer (and many of those available to download on the internet are poorly written), the program will consume memory and processor time in order to perform its duties. Unfortunately, since processor and memory are finite resources, such programs will steal processor and memory resources from YOU, thus we notice a performance degradation.

My advice would be to stick with the standard Windows delivered screen-savers, they are very efficient, tested by Microsoft, and there is an interesting enough selection of them.

Microsoft Windows, like any computer Operating System, is not perfect. Indeed, every year new problems and security vulnerabilities, enhancements and improvements are detected, fixed, added, etc, by Microsoft. When they are fixed, a software ?patch? is created, which is just that ? similar to the patch that some people would put over a tear in clothing, it fixes the problem, without having to ?buy new clothing?.

About once a year, Microsoft roll all of these patches and enhancements etc, into one large patch, which they call a ?Service Pack?. Service Packs are free of charge, often very big, and usually thoroughly tested by Microsoft and others.

For us Earthlings, the best thing to do is download them as soon as they are available and follow the instructions to install them. Note of caution, ONLY EVER download a Windows Service Pack from Microsoft?s website (), as all other copies have potentially been tampered with and could in fact be viruses.

Digital music is a large topic, and I will cover it in greater detail later, but I selected this question because it is an important issue for Earthlings.

First let?s explain the legal issue: When you buy music, in CD, tape or vinyl form, there is absolutely no legal issue with you making any number of copies for your own use. The key wording here is ?for your own use?. Once you copy it for a friend, or even another family member you are infringing the copyright of the material and are, in theory, subject to prosecution under the law. If you share your electronic copy onto the internet (and unless you know how to configure it to not do this, programs like LimeWare and Kazaa, WILL share your music on your behalf) then you are infringing these copyrights on a massive scale. Downloading a copy of the material, is not illegal, per se: Owning one, sharing one, copying it for others, is illegal.

There are lawsuits ongoing now in the USA, pursuing individuals who share such music.

The second issue, alluded to by your IT department is one of security. If I am malicious enough, I can take a virus, rename the file to ElviPresley.mp3, and place it in my shared folder. Thus, when you search for Elvis Presley within Kazaa, one of the files for download you will be presented with, is mine. You download it, when you try to play it, of course, it is unrecognisable as an mp3 music file, but, the programme has now been run on your computer and infected it, and you don?t even know it ? you just think the mp3 files you downloaded was no good.