http://www.gamespot.com/articles/actually-windows-10-free-upgrade-offer-does-not-ap/1100-6427384/

Earlier this year, Windows executive Terry Myerson said in an interview that all Windows users--even people with pirated copies of the operating system--would be eligible to take advantage of Microsoft Windows 10 free upgrade offer. But as it turns out, this was a misunderstanding. Pirates are out of luck.

"While our free offer to upgrade to Windows 10 will not apply to non-genuine Windows devices, as we've always done, we will continue to offer Windows 10 to customers running devices in a non-genuine state." Myerson said in a blog post published today.

"Non-genuine Windows has a high risk of malware, fraud, public exposure of your personal information, and a higher risk for poor performance or feature malfunctions," he added. "Non-genuine Windows is not supported by Microsoft or a trusted partner."

Myerson did, however, tease that Microsoft is preparing some kind of incentive to get people with non-genuine Windows copies to switch over to a legitimate copy of Windows 10.

"In partnership with some of our valued OEM partners, we are planning very attractive Windows 10 upgrade offers for their customers running one of their older devices in a non-genuine state," he said. "Please stay tuned to learn more from our partners on the specifics of their offers."

As Mary J. Foley of GameSpot sister site Zdnet points out: "Non-genuine Windows copies are not always pirated copies. Sometimes users unknowingly purchase Windows copies that certain resellers or retailers are passing off as legal, which are counterfeit and/or tampered with. Sometimes there are false positives, via which legal copies of Windows show up as illegally licensed."

Per the terms of Microsoft's free Windows 10 upgrade offer, all PCs running Windows 7 and 8 will be eligible for a free upgrade to the new OS for the first twelve months following Windows 10's launch. Microsoft has not yet announced how much Windows 10 will cost after this period.