Just keep those little screws out of the PC's innards

Installing the drive yourself may require a little help - and a lot of perseverance, writes

While the CD-Rom is one of the technological stars of the PC world at the moment, installing a CD-Rom drive can be an exasperating experience. Last time I tried, I struggled for about half an hour on my own. I eventually sorted out the problem with the technical manager of the manufacturer, but that took another hour.

There are various types of CD-Rom. The two basic ones are internal and external. Most people buy internal drives, which disappear neatly into the computer but can be tricky to install. The first step is to take the cover off your computer. This might seem frightening, but the only thing you really have to worry about is dropping one of the tiny screws into the innards of the machine. These can cause a short circuit so, if you drop one, don't just say, "Oh well, I am sure it will turn up." If necessary, turn the machine upside-down and give it a gentle shake.

Have patience as you ease the unit into place. First, you have to find the right place to bolt it in. Then you may have to move some small brackets out of the way, squeeze the drive into a tight slot and, possibly, discover you need a special bracket to make it fit properly. Another call to the PC or CD-Rom manufacturer.

Once the drive is physically installed, the real fun begins. Most internal drives use a technology called IDE, which is exactly the same as used by the main storage disk inside the PC. In most computers you can use spare IDE connectors to plug into the drive; alternatively, many sound cards have IDE connectors built in.

External drives normally come with a special controller card that slots into your PC. Once again, you have to open up the machine, but slotting in a card is far simpler than installing a CD-Rom unit.

Now to the software, where many pitfalls await. First you must install your "device drivers". These are small software programs which tell your PC how to talk to your CD-Rom. They are supplied on floppy disks and can usually be installed without trouble. However, about 10 to 20 per cent of installations do run into a problem, the most common of which is an "interrupt clash". You will need to change the interrupt settings on your CD-Rom, either by flicking a tiny switch on the controller card or by giving a software instruction on the keyboard.

An alternative form of connection, called SCSI (small computer system interface), is beginning to become popular. SCSI is really aimed at the business market. It allows several devices to connect into a PC via one controller. This is usually a more expensive approach, but it can be much more flexible than the IDE. It was an SCSI connector that caused my problems with the wonderful six-CD multichanger Quad speed CD-Rom drive machine I had on loan. It was worth it in the end.

If you are using Windows 95, things should be easier. One of the great supposed benefits of the new software is "Plug and Play". When you pop a new CD-Rom drive in, your PC automatically detects it and changes all the settings for you. The trouble is, this will work only with Plug and Play-designed CD-Rom drives - which are only just coming on to the market. It is worth pointing out that for the Apple Macintosh community, Plug and Play has been around for about eight years.

The most important point to remember with a CD-Rom drive is to buy from a reputable supplier. "Access to proper support is absolutely essential as more ordinary people are buying CD-Rom drives," says Ian Skelton, technical marketing manager for Creative Labs, the world's biggest supplier of drives. "We have a dedicated support staff of 60 people dealing with enquiries from all over Europe. You really do need to make sure that the support is there. But a good dealer will also always be helpful and there are some who will really go out of their way to help."

You should not really have any problem installing a CD-Rom drive. If you do, persevere and you will get it working. Probably.