Apple Computer - the maker of the Macintosh computer and hugely popular iPod music device - has rolled out the first-ever software patch to run Microsoft's dominant Windows operating system on its PCs, a move that could draw millions of new buyers.

By enabling the move to Windows, the world's number one operating system, Apple hopes to draw people who want Macs, considered by many as easier to use and more stylish, but prefer the Windows operating system.

Apple said the "Boot Camp" software, available immediately as a download, enables Macs powered by Intel chips to run either Windows XP or Apple's Mac OS operating system software.

Apple's rivals Dell and Hewlett-Packard primarily use Microsoft Corp.'s Windows software.

"We think Boot Camp makes the Mac even more appealing to Windows users considering making the switch," said Philip Schiller, Apple's senior vice-president of Worldwide Product Marketing.

In addition, with the patch, Macintosh users will now likely be able to run some games and other software on their Mac OS X computers without buying a separate Windows based computer.

The final version of Boot Camp will be available as a feature in the upcoming Mac OS X version 10.5 "Leopard" personal computer. Apple said it will not provide support for installing or running Boot Camp and does not sell or support Microsoft Windows software.

California-based Apple said last June it would shift to microprocessors made by Intel, the world's biggest chipmaker, from those made by International Business Machines. It plans to move its entire Macintosh line to Intel chips by the end of 2007.