Vendors supporting Microsoft's enthusiasm for Tablet PCs are in bullish mood, predicting that the technology will make up a big chunk of laptop sales.

Despite analyst predictions that Tablet PCs will fail to make a big impact next year, the five firms selling them believe they will account for a significant proportion of laptop sales over the next 12 months.

The most buoyant statements came from RM, which is targeting the education sector, and Fujitsu Siemens. Both companies estimated that Tablet PCs would make up around 30 per cent of their notebook sales over the coming year. Hewlett Packard put its money on around 20 per cent of sales, with Toshiba a fraction more cautious at 15 per cent.

PC manufacturers are banking heavily on customer enthusiasm for pen-based data input and claim that those in the education and health sectors will gravitate towards Tablet PCs because of the freedom and versatility they offer.

But analyst Gartner recently painted a much gloomier picture, estimating that Tablet PCs would only account for 1.2 per cent of worldwide notebook shipments in 2003.

Although Gartner expects curiosity to spark an initial surge in sales, the analyst believes it will take four years for Tablet PC sales to reach the levels predicted by the vendors backing the format.

Critics cite the high price and limited applications as two main drawbacks of the Tablet PC.

While one RM model targeted at schools is just £799, the typical launch price will be about the same as a compact notebook - approximately £1,300 to £1,500. But the units do not include features that are standard on notebooks, such as an integral DVD or CD-Rom drive. These are only available separately.

On the applications front, Office 2000 will have no support on Tablet PCs and a vast amount of software will be unable to take advantage of the new features. However, an Office XP pack for Tablets is already available and some independent software vendors are revising their software to support pen input.