The personal computer industry has been getting away with murder. For at least 10 years it has sold hardware and software that seldom lives up to the claims made in the adverts and on the packaging. Often it does not work at all, or stops some other function working.

In the flakey world of the Wintel PC (IBM clone computers which use Intel chips to run Microsoft DOS and Windows software) everything is almost-but-not-quite compatible. So everyone at the selling end can blame someone else. Printers print hash signs instead of pounds sterling; modems sit dumb or display gibberish; adding a mouse, scanner or sound card blocks some other device. But the worst is fitting a CD-Rom drive to a PC and using it to run game, education or “infotainment” discs. Even when the system works and the disc plays, the content is often disappointing.

Resistance to the CD-Rom rip-off is growing, as more users learn that they are not “the only person to complain”. Some dealers will now only stock CD-Roms on a sale-or-return basis. Dissatisfied customers are now returning 25 per cent of discs purchased.

Owners of Apple Macintoshes chortle and say the only easy answer is to “buy a Mac”. But thanks to Apple’s early refusal to license the Mac operating system and the generally higher cost of Macs, at least nine out of 10 computers are Wintels. Therefore it is more realistic for their users to learn to spot potential problems.

The most important rule is to read the packaging. A small-print panel on the side of the CD-Rom box will usually list the minimum requirements for playing the disc. The list includes memory size (Ram), free hard-disc space, processor type and speed, CD-Rom drive speed (hopefully at least twice normal speed), colour display type (should cope with 256 colours) and any extra peripherals needed, such as a mouse, sound card and MPEG decoder for movie video.

Ignore this list at your peril. If running the CD generates error messages such as “insufficient memory” or “insufficient disc space”, or produces only bursts of sound and jerky motion, you will have no come-back on the dealer if the PC falls below clearly-stated requirements.

There are minimum software requirements, too. Most CD-Roms work only on a PC which has Windows as well as MS-Dos. Windows must be Version 3.1 or later.

Even when a PC meets all the hardware and software requirements, there is no guarantee that a CD-Rom will play. The Rom must first be “installed”, that is the CD must copy a batch of files on to the hard disc inside the PC. It then creates icons which appear on screen and allow the program to be started with a mouse click. The Rom will usually need to copy several megabytes of files. If the PC runs out of disc space, installation will fail. Even if there is free disc space the process may still fail. And the error messages on screen seldom identify the cause of failure.

There may be conflict with programs already on the PC. If the names of old and new program files are the same, the new program may overwrite the existing file (perhaps stopping them working) or refuse to write its own (thereby condemning itself to failure). If the new program alters existing system set-up files it can stop batches of other programs working.

A good help line is essential. An understaffed and underinformed service is useless. Software reviewers should try out help lines as well as programs to let the public know which software producers know and care about their products.

The publicity campaign Microsoft mounted for the launch of Windows 95 led even level-headed consumers to believe that the new system (which replaces existing DOS and Windows) somehow magically makes PCs easy to use. This may one day be true but not yet.

To run Windows 95 efficiently, a PC should have at least 8 megabytes of memory (Ram), a high-speed 486DX or Pentium processor and hard disc with at least 250 megabytes capacity. It should also have new “Plug and Play” BIOS software on its Rom microchips. When this kind of set-up is used, an unskilled user should at last be able to play CD-Rom software almost as easily as an audio CD.

A final word of warning: whereas audio CDs leave nothing in the machine after they have played, CD-Roms copy several megabytes of data to the PC’s hard disc. So the PC will eventually fill up. Deleting the Windows icon for an installed CD-Rom is easy but it leaves those bulky files on the hard disc. They are often scattered and some are hidden. Inexpert removal of files can stop Windows working properly.

The only safe way to remove Rom files is to use an “uninstall” program. Modern CD-Roms come with their own, but the publishers don’t advertise this feature as they don’t like to admit that anyone might want to remove a program.

So ask the dealer before purchase whether a Rom comes with an uninstall option. If the dealer looks blank or is unhelpful, find another. When buying CD-Roms, a knowledgeable dealer can be a very valuable asset.