Have you ever felt like thumping an unco-operative PC? You're not alone. One quarter of 4,200 computer users questioned in a recent survey admitted they had physically attacked their computers.

"Taking frustration out on an inanimate object does help people vent their frustrations," said Richard Andels, a psychotherapist who specialises in anger and domestic violence. "Unfortunately it rarely does the object any good."

The internet survey, conducted by PC firm Novatech, also revealed some of the more stupid mistakes made by PC users – the kind of foolishness that drives technical support people round the bend.

One person admitted to paying an IT engineer a £56 call-out fee and £25 for the first hour to fix a seemingly faulty monitor, only to find it hadn't been plugged it in.

"We have many complaints where users ring up because their PC is broken which, when we investigate further, we find they have tried to fix by thumping and kicking," said a spokesperson for Microsoft's helpline. "One guy even threw his PC out of his window."

Another man carried out a spellcheck on an report, clicking 'ok' to approve the computer's correction of his spelling of 'borehole'. The next day his client was bemused to receive the following claim: "According to the results of the examination, the brothel has become contaminated."

"One of the most surprising and pleasant results was just how much humour and social interaction [computers] cause," said David Furby, head of Novatech. "Although in many of these cases, it's probably not the sort of social interaction people were expecting."

But a worrying five people admitted to having more than 10 computers in their homes. One person said he had 1,000 computers in his house – obviously a serious PC Advisor reader, with an enormous house.