The successor to the Windows operating system -- codenamed Whistler -- will ship in the second half of 2001 with different prices for home user and business versions, and a server version scheduled for release several months after the client software, Microsoft confirmed Wednesday. Whistler beta 1 was released for testing on 31 October. The final version will be the first attempt by Microsoft to offer a single range of products, all built on the same code base, to the consumer, business and server markets. Personal Client will be designed for home PCs and Professional Client for business PCs. There will also be a range of server software, and an embedded version for closed hardware devices such as network storage schemes. Currently Microsoft sells Windows Millennium (Me) and Windows 98 to home users. The company recently released Windows 2000, the sequel to NT, for business users and there is also a range of Windows 2000 server software and an embedded version of NT. Whistler is based on the NT/2000 codebase. Speaking at a press conference Wednesday Jim Ewel, Microsoft's vice president IT infrastructure and hosting solution group, confirmed that the home PC and business PC versions of Whistler would both ship several months before its server client, and probably six months ahead of the embedded operating system. "The personal client and the professional client will be available in the middle of next year. Server versions should ship two to three months later". Ewel would not give any pricing details, explaining that such information was only available around six months before software release. However, he confirmed that the consumer desktop product would be cheaper than the business products. "People should not assume that each offering contains the same code, as there are several differences", Ewel explained. "The personal version of Whistler will be priced appropriately for a consumer audience, and the pro version at a price appropriate for a business audience". The embedded version of Whistler will be released around three months after the server but according to Ewel it will not be used in Microsoft's gaming console Xbox. According to Ewel, Whistler will only mean incremental improvements for business users but will be a more stable platform for home users. "The consumer product represents a revolutionary release in reliability. This is the most dependable Windows ever," Ewel claimed. Whistler will include a new level of security, which Ewel explained was in response to virus attacks such as last year's ILOVEYOU virus. Users can decide which of 40 different executable files are allowed to run on their machine, including an option to only run signed files. Corporations running the Professional Client will be able to set company-wide policies on which files can run on their machines. This system is intended to prevent malicious code attaching a machine, with the option to only execute signed files intended to protect novice users who might not know which files are safe to run. Back in June Microsoft released details of .Net, a initiative to produce a series of Web-based software services. Whistler will include few .Net innovations though. The final release of the operating system will contain several visual design changes, most which have not been incorporated into the first beta release. Take me to the Windows Special Take me to ZDNet Enterprise Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet News forum. Let the editors know what you think in the Mailroom. And read what others have said.