With all the hoopla over the release of the final version of the Linux 2.4.0 kernel last week, Microsoft's delivery of an interim beta version of its Windows 2000 successor, codenamed Whistler, got lost in the shuffle. But according to Whistler testers, Microsoft issued build 2410 of its next version of Windows on Thursday. New in this build are many user-interface tweaks, as well as the incorporation of new antipiracy code. Microsoft issued Whistler Thursday, only to pull it off the beta test Web site shortly thereafter, due to installation-key problems. The company subsequently reposted the beta for download by Microsoft's technical beta testers over the weekend, testers said. Whistler is the first release of Windows in which Microsoft is aiming to deliver a full range of flavors, from a 32-bit personal version to a 64-bit datacentre version, all based on a common NT kernel. The personal version of Whistler and some of the server versions are expected to ship before the end of 2001. In recent weeks, Microsoft officials have christened Whistler the most significant Windows release since the company issued Windows 95. Microsoft chairman Bill Gates provided a sneak peek of Whistler during his Consumer Electronics Show keynote speech over the weekend and talked up the operating system's importance to the "always-on" PCs of the future. Microsoft officials did not respond by deadline to a request for updated information on Whistler. Microsoft delivered the first beta of Whistler in late October. Beta 2 is expected some time in February, according to sources. Build 2410 is the first Whistler beta that Microsoft made available widely since Beta 1. A number of testers managed to grab the code using their existing Windows 2000 product installation keys and began dabbling with it over the weekend. As reported on Windows enthusiast Web sites, including WinInfo and ActiveWin, Whistler 2410 includes a number of user-interface tweaks. Built into 2410 is Internet Explorer 6.0 (IE6 build 2411). IE6 is expected to enter widespread beta testing in the next couple of months. Among the interface changes with Whistler build 2410 is the introduction by Microsoft of alpha-blending technology, according to one tester. Alpha blending allows icons to blend into the background of a screen. In order to enable this feature, driver makers will have to support Microsoft's new alpha blending format, however. The most potentially controversial addition to Whistler 2410, however, is antipiracy code that Microsoft is calling "Microsoft Product Activation for Windows", (WPA) according to testers. The technology is similar to the Office Activation Wizard that's part of Office 2000. WPA will tie a Windows product key to one specific PC in order to reduce casual copying. In order to "activate" it, a customer will send data about the installation, such as product ID number and hardware identifier, to a Microsoft-run licence clearinghouse. The clearinghouse won't allow the use of the customer's product key on a PC different from the one originally activated. Microsoft plans to deliver WPA in all 32-bit versions of Whistler except those sold to volume-licensing customers and the so-called "Royalty OEM initial install images" provided to PC makers, said sources close to the company. Microsoft is expected to add similar antipiracy technology to Office 10 and Visual Studio .Net, sources said. Take a look at ZDNet's Whistler screenshots. 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.