The 13.6% year on year rise will be powered by the replacement of machines bought in the late 1990s the run-up to the millennium. Almost 100 million PCs will be replaced this year, with 120 million more being ripped out next year.

The PC slump of recent years came about in large part because corporations opted not to replace the PCs they bought in 1998 and 1999 according to the expected three year cycle. PC vendors have been repeatedly caught out by false upgrade dawns in recent years.

However, Gartner said yesterday that first quarter figures suggested that the long-awaited upgrade cycle is finally well under way. The expiring of support for the operating systems these machines carry has been a major motivator for replacing them, and support concerns will continue to play a major role in future replacement cycles, the analyst firm predicted.

Healthy economic growth is also contributing to the rise in PC shipments, Gartner said, and should continue to influence shipments throughout this year.