Microsoft seems to be rethinking its entire Windows road map, including plans for future versions of its integrated Internet Explorer browser. Last week Microsoft confirmed that it has tabled its "Neptune" and "Odyssey" Windows updates, preferring to converge its code base around the NT kernel with a future version of Windows that is code-named "Whistler." Last Monday the company sent an email to beta testers awaiting its next Internet Explorer (IE) beta -- formerly code-named "Haley" and currently referred to as "Mars" -- notifying them that the Mars beta has been postponed. Microsoft officials told testers that the company is "rethinking some of our most basic assumptions" regarding the future of IE, according to testers who received the email and requested anonymity. Mars is a future version of IE tailored for home users, testers said. Beta testers who have offered Microsoft feedback on betas of IE 5.x have been expecting the first beta drop of Mars for the past several months. Microsoft solicited beta testers for Mars last October. One Mars tester explained the product this way: "It is part of IE and is supposed to be for casual users, and it is supposed to aid them in using the Net. I think it will have the Activity Centres integrated, and it will piggyback Win98 or Windows 2000 from what I got earlier about it." Activity Centres are groupings of tools related to specific tasks, like digital photo editing or music production. Activity Centres were slated to be part of the "Millennium" Windows update. But testers said Beta 2 of Millennium did not include Activity Centres or a number of other features originally slated for this release, which is due to ship in the third quarter of this year. Microsoft officials, contacted for comment on the status of the Mars beta and the reason for its postponement, declined to comment. While continuing to claim that IE is an inseparably integrated piece of the operating system -- a claim that is central to Microsoft's defense in its current antitrust lawsuit with the US Department of Justice -- Microsoft has continued to enhance IE independently of the rest of the OS. In December Microsoft posted the first public beta of IE 5.5 to its Web site. IE 5.5 is expected to be part of the Millennium update to Windows 98 Second Edition. IE 5.5 includes improved support for DHTML behaviors and support for vertical text, according to Microsoft. It also adds support for Cascading Style Sheets Level 1 and Synchronised Multimedia Integration Language (SMIL). While the company is marching ahead with point-product updates, it seems to be reprioritising its bigger-picture strategy. Microsoft moved all its Windows releases under Group Vice President Jim Allchin late last year. At that time the company also announced it was moving David Cole, a longtime leader of Windows and IE teams, to a newly minted Consumer Services division, part of Rick Belluzzo's Consumer Group. Since Microsoft announced three weeks ago that the company was refocusing product development around its Next Generation Windows Services (NGWS) architecture, the company has made several changes to its previously planned product lineup. Microsoft is scheduled to outline its NGWS vision sometime in April at an event dubbed "Forum 2000." What do you think? Tell the Mailroom. And read what others have said. Take me to the Windows Special