Microsoft has confirmed that Windows 10 will be available a free upgrade for the first year after release, Digital Spy reveals.

Windows 7, 8 and 8.1 users will not be charged to download the new operating system during the first 12 months of its lifecycle.

"For the first year after Windows 10 is available, we will be making available a free upgrade to Windows 10 for all devices running Windows 8.1," said Microsoft operating systems chief Terry Myerson.

"Once a device is upgraded to Windows 10, we'll be keeping it current for the supported lifetime for the device."

Set to launch later this year, Windows 10 is a multi-platform offering designed to offer a seamless experience across PCs, mobile devices and games consoles.

Windows Phone 8.1 users can also upgrade to Windows 10 for free during the first year.