Microsoft is set to release the fourth version of its Windows CE operating system for clamshell-style handheld PCs Thursday. Called Handheld PC 2000, the new version offers a few improvements on its two-year-old Handheld PC Professional OS. Devices that supported earlier versions of Handheld PC have never lived up to the hype by Microsoft and its hardware partners. The devices, launched nearly four years ago, were supposed to take over the PDA market, offering streamlined desktop and notebook PC capabilities with greater portability and a lower cost. Somehow, consumers never got the message. As a result, the devices were criticised either for not offering enough capabilities -- as in the case of those based on Handheld PC -- or for having too many, as were Pocket PC-based handhelds. Through several upgrades, which saw the OS split in two to address the increasingly popular PDA market, Handheld PC found its market niche, and the latest features address those customers. The new generation of devices using the Handheld PC OS are expected to be on the market within the next few weeks at prices ranging from $500 to $1,000 (£344 to £688). The devices will address specific industries, such as health care, insurance and financial services. The new OS adds thin-client software that was previously available for the third version of the OS. A new browser compatible with IE 4 offers what Microsoft officials call greater consistency with the Windows desktop and, finally, the media player available on the Pocket PC platform has also been added to the Handheld PC platform. There are two types of devices based on the Handheld PC platform: Some are similar in size to sub-notebooks, such as IBM's ThinkPad 240 and Toshiba's Portege 3400; and others are tablets, such as Vadem's Clio. Of the original major manufacturers supporting the OS -- including Compaq, HP, Casio, NEC, LG, Sharp and Philips -- only HP, NEC and Mainstreet Networks, which bought the rights to Vadem's Clio device, remain. IBM, Casio and LG have not made plans for their units clear. The new generation of devices based on the Handheld PC platform are expected to be on the market within the next few weeks at prices ranging from $500 to $1,000. The devices will address specific industries, such as health care, insurance and financial services, according to Doug Dedo, Microsoft's group product manager for mobile devices. Had the companies done a better job of communicating to consumers the benefits of the handheld platform, the devices may not have been relegated to such niche markets, said Mike McGuire, an analyst at Gartner Group's Dataquest. McGuire has not given up on the Handheld PC platform, however, saying that the more options there are in the market, the more vitality there will be. There is also space in the market for handhelds, which were initially confused as competitors to notebooks, according to McGuire, who sees more growth potential in tablet devices over clamshell-style handhelds. In the American West it was grizzly bears and stagecoach robbers. In the digital world, it's cyber vandals -- news of the first ever virus aimed at PDAs had some people's hands trembling. Jesse Berst is here to tell you how vulnerable your handheld is and how to make it safer. Go to AnchorDesk UK for the news comment. What do you think? Tell the Mailroom. And read what others have said. Take me to the Mobile Technology Special