Microsoft is taking a step back in its long-running effort to stimulate interest in tablet PCs, Bill Mitchell, corporate vice president for the Windows client business, told delegates at WinHEC in Seattle.

"The first models of the Tablet were a noble attempt to get to the end goal very quickly. But, as it goes with any new technology, it is very difficult to move customers to the end goal. So we have taken a step back," he said.

Microsoft launched the Tablet PC in 2001. But last year the pen-controlled portable computers made up just 1.3 per cent of overall notebook sales, according to data from analyst firm IDC.

Mitchell explained that Microsoft developed the device in an effort to create a highly portable computer that every person on earth could carry. The company aims to have 100 million "portable PCs" on the market by 2008.

To increase the appeal of the Tablet PC, Microsoft earlier this month revealed an Experience Pack containing applications specifically designed to use the digital ink capability in the device.

The bundle contains a daily crossword puzzle, drawing tool and software that allows the owner to exchange media files between a desktop system and Tablet.

Mitchell admitted that he was inspired by the rise of the mobile phone. "Customers are not getting the value out of mobile PCs that they find in mobile phones. Why is that? PCs are so much more versatile," he said.

PC makers need to develop new form factors, increase the battery life and provide users with instant access to information, according to Mitchell. "The goal is to get much closer to the utility of a mobile phone," he said.

The Tablet is a start, but more needs to be done. With the addition of an auxiliary display, users can access their data without opening their laptop computers. Bill Gates demonstrated the technology in his opening keynote on Monday.