The world's largest software maker is publishing a new version of the operating system that runs the vast majority of personal computers, or PCs.
It is called Windows 7, and Microsoft officials say it fixes many of the problems that frustrated customers in an earlier version of Windows, called "Vista."
The system, released Thursday, is available on new computers and as an upgrade for some older PCs. Reviewers say the new system is faster, more secure and easier to network than its predecessor. They report the difficulty of upgrading to Windows 7 is its biggest drawback.
Critics have called Windows 7 Microsoft's first real competitor to rival Apple Computer's operating system (OS X), adding it may be the company's best bet in undercutting Apple's recent sales gains.
Some information for this report was provided by AP and Reuters.