Research firm Gartner slashed its growth forecast for the global PC market this year to 3.8 per cent from 9.3 per cent, citing slower economies in Western Europe and the United States, and a boom in media tablets.
The success of Apple's iPad has dented consumer demand for personal computers, while the long-hoped for recovery in the corporate and government PC replacement cycle has been derailed by the US and European debt crises and associated fallout.
"An increasingly pessimistic economic outlook is causing consumer and business sentiment to deteriorate in both regions," Ranjit Atwal, research director at Gartner, said in a statement on Thursday.
Gartner said it expects consumer spending to tighten in response, while business spending would also tighten but to a lesser degree.
"U.S. consumer PC shipments were much weaker than expected in the second quarter, and indications are that back-to-school PC sales are disappointing," Atwal said.
The slowing, changing market has hit traditional leaders of the PC market.
Hewlett-Packard stunned markets in August when saying it may shed its PC business -- the world's largest after the $25 billion acquisition of Compaq in 2002 -- as part of a wrenching series of moves away from the consumer market.
Those included killing off the TouchPad tablet computer in the face of stiff competition from Apple.
"Media tablets have changed the dynamic of the PC market and HP's decision to rethink its PC strategy simply highlights the pressure that PC vendors are under to adapt or abandon the market," said George Shiffler, research director at Gartner.
No. 2 PC vendor Acer Inc last month reported the first quarterly loss in its history, as it took charges to reorganise in a troubled first half, and said it would be impossible to break even for the full year.
"Vendors' tried and true business models are failing as traditional PC functionality is extended to other devices, and users continue to lengthen PC lifetimes. Vendors only seem to be failing as they look for quick fixes," Shiffler said.