Slowing world economies and the knock-on effects of September’s US terrorist attacks could impact the PC business in the short-term, but long-term prospects are bright, according to Bill Gates.

Gates, Microsoft’s chairman and chief software architect, said today in Tokyo that it's not the end of the world as far as flogging boxes is concerned.

"There could be a period of time here where the kind of sombreness that comes with this tragedy affects business," he said, referring to the attacks. "I'm not somebody who can predict that. However, I can say that, already as the economy was slowing down, Microsoft was one of the few companies that was able to continue to increase our R&D on products such as tablet PC, speech recognition, Xbox or Pocket PC."

Despite the current troubles and demand for PCs being eaten away by the increasing popularity of PDAs (personal digital assistants) and internet-enabled mobile phones, Gates is optimistic about the future of the PC industry.

"Throughout the history of the PC it has been underestimated again and again," he said. "This is not the first year we have had people saying, 'What about the PC?' We had that happen when we had a market of one million PCs, when we had a market of 10 million PCs and now the market is well above 100 million."

New PC applications yet to be fully realised such as real-time communications, notetaking and their role as music storage devices were cited by Gates as reasons for his optimism.

"The PC, as we improve it, will be the device of choice anywhere you want the large screen. The market for small screen devices will be optimised by having these platforms work together," he added.