Consumers who buy a new PC between now and January 31 can pay $US14.99 for an upgrade to Windows 8, the next version of Microsoft's PC operating, according to Microsoft.
Steve Guggenheimer, head of Microsoft's OEM division, disclosed the price in his keynote address at the Computex trade show, but he didn't provide a release date for Windows 8, as some had expected.
Analysts and PC makers have said they expect Windows 8 to ship before the end of the year. The fact that the upgrade offer ends Jan 31 suggests Microsoft expects it to be out by that date at least, possibly earlier.
This latest upgrade price is for consumers only, according to a slide that appeared briefly during Guggenheimer's presentation. It's limited to one upgrade per PC and five upgrades per person.
Such offers are intended partly to stop people from holding off on buying a new PC because they know a new OS release is on the horizon, something that could be painful financially for Microsoft and its partners.
PCs sold in the transition period to previous versions of Windows came with an array of coupons from Microsoft and PC vendors offering free, subsidised or half-price upgrades. For many users, upgrades on a new PC from Windows Vista to Windows 7 were free or nearly free.
Much of Guggenheimer's keynote was given over to a demonstration of Windows 8, the biggest update to Microsoft's PC OS since the move from 16-bit to 32-bit computing with Windows 95.
The OS is optimized for touch computing and includes a completely new interface, called Metro, that features large tile icons a bit like Windows Phone 7. The old Windows desktop is still available underneath as an option.
It's also the first release of Microsoft's PC OS that will run on ARM-type processors as well as the x86 chips from Advanced Micro Devices and Intel.