Software giant Microsoft Corp. has released new test versions of what company co-founder Bill Gates called its three most important products: Windows Vista for desktop computers, Windows for servers, and the Office business software suite.

The new beta, or test, products were unveiled May 23 at Microsoft’s annual Windows Hardware Engineering Conference, a highly technical event for the companies that produce gadgets powered by Microsoft products. The test releases are important because they help those companies prepare for the final launch of the new versions of Windows and Office.

The betas also are key for companies, school systems, and other organizations that are planning to deploy the new Windows and Office products and want to make sure they will work well with other software.

Microsoft recently delayed the consumer release of its Windows Vista operating system and Office products until January, missing the all-important holiday season and dealing a blow to some hardware manufacturers who were hoping for a holiday sales boost. The company does plan to release the products to its enterprise customers in November.

On May 23, Microsoft laid out plans to help customers understand whether new hardware they buy before Vista comes out will work well with it. Mike Sievert, a corporate vice president in Windows marketing, said Microsoft also plans a marketing push around the holiday season to help spur hardware sales even before Vista releases, but he declined to provide details.

The Windows server operating system is due out by the end of 2007.

Gates and other Microsoft executives sought to tout the benefits of organizations using all three products together to improve security, more easily work together, and more quickly find documents and other information.

Microsoft also said the new technologies would make it easier for organizations to load software onto their computers.

For consumers, Microsoft said, Windows Vista will make it easier, faster, and more enjoyable to do things like find family photos and watch movies. Microsoft is also placing particular focus on using its products in mobile devices, because the company believes that more people will start using gadgets such as “smart” cell phones for everyday tasks.

Microsoft is depending on successful launches of its new Windows and Office software, because the two products are the major cash cows for the world’s largest software maker.