Microsoft executives said Friday that the company will not offer Windows 10 for free to those without legitimate licenses to Microsoft’s software, as the company had previously seemed to say.

Terry Myerson, executive vice president of operating systems for Microsoft, wrote Friday that the company will provide “very attractive” offers to those who wish to upgrade from what he called a Windows operating system in a “non-Genuine state” to Windows 10. But, he said, it will not be free.

“While our free offer to upgrade to Windows 10 will not apply to Non-Genuine Windows devices, and as we’ve always done, we will continue to offer Windows 10 to customers running devices in a Non-Genuine state,” Myerson wrote. “In addition, 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.”

If Windows thinks that the software isn’t genuine, it will create a “watermark” on the machine, notifying customers that they’re running an illegitimate copy of the software. If that happens, a customer will either need to upgrade or return the machine—assuming they just bought it—to the manufacturer itself.

“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,” Myserson added. “Non-Genuine Windows is not supported by Microsoft or a trusted partner.”