Microsoft on Tuesday moved to restore faith in its ability to launch key products on schedule, releasing second test versions of its Windows Vista operating system, Office 2007 programs suite and Windows Longhorn Server software.

Announcing the Beta 2 versions at a conference in Seattle, Bill Gates, chairman, said it was the first time there had been such a synchronised release of “the three most important Microsoft products.”

“Today’s a milestone for us in terms of the huge investment and big innovation going into the next major version of Windows and all of the complementary products,” he said.

Analysts had begun to doubt whether Microsoft could stick to a new deadline it set itself in March of shipping Vista on new PCs from January 2007. It had earlier targeted a November release after failing to get the new operating system ready by 2005.

Microsoft had promised the second beta would be available before the end of June, prompting the Gartner research firm to warn earlier this month that this did not leave enough time to test such a complex piece of software. It predicted PC buyers would have to wait until at least next March to get Vista. But this May release appears to give Microsoft more breathing room to get the software right before it is released for manufacturing.

“Not only are we happy we are hitting our targets on schedule, but this gives our corporate customers the chance to get a sense of how all three of these work together,” said Neil Charney, senior director of the Windows client group.

Mr Charney said half a million IT and corporate customers had been testing exisiting betas and the new test version would be distributed more widely to include technology enthusiasts.

During the conference, new features were demonstrated including the ability of laptops with wi-fi cards to exchange files with one another, without the need for a wireless network. They could also send presentations to a wireless projector.

Microsoft shares closed 0.4 per cent lower in New York at $22.79.