Microsoft has confirmed that a beta version of its delayed Longhorn operating system will be available before the end of the year.

The successor to Windows XP, originally scheduled for release late this year, will now only be available in beta version during 2004 - with Microsoft unwilling to commit to a commercial rollout date.

Microsoft says a final release of Longhorn will be available once the software giant has received feedback from beta trials and tailored the product.

A company spokeswoman has denied claims circulating this week that delays were a result of security concerns over its software.

Microsoft is also likely to deliver an interim update of XP before the launch of Longhorn, as well as upgrades to Windows Server 2003.

Analyst firm Gartner says Microsoft should be more forthcoming with information on software releases so businesses can plan IT strategies.

Gartner recommends that businesses should plan to introduce XP now to protect themselves against changeable Microsoft release cycles.

Microsoft should release timelines and feature information about any interim versions of Windows, so that businesses hesitant to introduce XP can be informed, according to Gartner.

The analyst said that Microsoft should also release a statement about its support of Windows 2000 Professional, which it plans to stop selling at the end of March.

In 2001, Microsoft spoke about releasing Longhorn in late 2004, but then said it was likely to delay the release until the second half of 2005, according to Gartner.

But at Microsoft's developer conference in October 2003, the implication was that Longhorn would be more likely to ship in 2006, the analyst said. The delay may be longer, with Longhorn not shipping until 2007, it predicted.