The advert promised the earth, the reality was a wonky PC and weeks spent trying to get some sense or satisfaction out of `customer service'. Yes, Pru Irvine was in the grip of computer rage.

Road rage has nothing on this. This creeping hysteria transcends race, creed and colour and starts, I suspect, as you sign the standing order agreement.

To put the subject into context I should tell you how this came about. I was leafing through the newspapers when I came across a full-page ad saying, "I want it up and running":

"A top class PC on my desk as soon as possible. That's in days not weeks. I haven't got time to worry about installation. I need someone to take care of all that for me. Naturally, I want to order it over the phone and it's got to have the latest software. I also want a full on-site warranty backed up with technical support from people who really know (and care about) what they're doing ..."

And all that from the world's No 1 PC manufacturer - Compaq. I'll have that, I thought. It took about two weeks to arrive. The fax didn't work and the keyboard made funny marks like a "*U" when I wanted a "%" and so on. I phoned the help line because I've got a free year's customer service and support deal. Well, of course, it didn't work - the integrated fax, to be precise. I was pushed from department to department, from England to Scotland. The funny thing was that every time I talked to someone new they denied the existence of the last person I'd spoken to. Each and every one gave me their personal guarantee. It was decided I should have a replacement, but no one knew when. I explained, with the minimal amount of bile, that I'd missed a work deadline, was about to miss another and had spent almost a day on the telephone.

The man with the new machine arrived. When I suggested he test the fax, he threw his hands above his little chest: "More than my job's worth." He left, with the original machine still standing on the desk and the replacement still in its box. I can't tell you much more because I can feel the urge to slam the keyboard through the screen as the memory rekindles.

What I can tell you though is that computer rage is attacking people of all ages and IQs. According to Martin Courtney of PC Advisor, it falls into two categories: "There's the personal kind when the machine won't do what it's supposed to do. That's very frustrating and can lead to swearing and hitting. Then there's the kind that develops when you can't get the support people out to help."

It's a case of "buyer beware" he says. These days computers are generally reliable and the price ranges are very similar. But it's all in the small print. You have to look beyond the promised support contracts. Will they fix the machine on-site, replace it or take it away leaving you with nothing?

"The big companies are not as good as they promise," he says. "Many machines are overpriced because you're supposed to be paying for the back-up support. The manufacturers need to pull their socks up. Instruction manuals and documentation used to be very good but now costs have put paid to that."

There's also no way of telling which companies are good or bad at keeping their support promises as there's never been any research done in this country. So people like me are at the mercy of the manufacturer's hype. I don't know whether I'm pleased or not to find I'm probably one of thousands.

Clive Akass of the magazine Personal Computer World recognises the syndrome all too well, but just can't help feeling a wee bit sorry for both the manufacturers and their products. It's a cut-throat business on tight margins, he says. "You don't expect a car manufacturer to tell you how to drive. Everybody wants to kick the screen in at some point but computers are very forgiving. They let you get it wrong more often than humans." Sweet. But I'm not seduced. I'm neither grateful to my PC for being there nor do I want to cuddle it.

Because one computer is much like another people are differentiating on things like service. EXACTLY. So, where was I? The new machine also turned out to have a fault. I wrote to Compaq's MD saying all the sorts things you'd expect someone suffering from Computer Rage to say and was greeted by a resounding silence. Some two weeks later, after a couple of wild telephone calls from me and a few feeble apologies from them, I get a call from the director of Compaq's Consumer Division, Ian Jackson.

Lots of sorry, sorry, sorry. You're the only complaint of this kind that I know about. We obviously need to do a lot more work on our back-up skills, we need to empower the people who deal direct with our customers, reconsider our engineer training programmes, etc, etc. "We want," said Mr Jackson, "to be in constant contact with our customers." In my case, of course, they've succeeded on that one. They also agreed to some compensation - undecided as yet.

It was only when I had got right to the top that the empire swung into action. Compaq's training manager and their technical support manager have spent nearly six hours trying to fix the demon in the black box. Have they? No. I await yet another PC.

Excuse me, I must run now. It's 10 minutes since I last called Compaq.