In a post to Microsoft's Australian Partner Network--and first spotted by Neowin--Alex Snelson, a Windows product marketing manager at Microsoft Australia, clarified what will happen after the deadline:
"Microsoft will offer a free upgrade to Windows 10 for qualified Windows 7, Windows 8 and Windows Phone 8.1 devices in the first year. After the first year, upgrades will be paid via boxed product and VL Upgrades."
So there you have it. If you don't make the leap to Windows 10 within a year of its summer 2015 launch, you'll have to pay if you choose to do so in the future. And if you're building a new PC, remember that Windows 10 isn't truly free--the offer's only good to upgrade PCs currently using a legitimately licensed version of Windows 7 or 8. DIYers will still need to buy a copy of Windows. (Pricing for Windows 10's various versions haven't been announced yet.)
Want to give Windows 10 a whirl before you take the plunge with your primary PC You can test the Windows 10 preview for free right now , and it'll eventually be updated to the RTM (read: final) version of Windows 10. Be sure to check out these cool new features first and try these powerful tips, tricks, and tweaks if you give it a whirl.
Why this matters: This confirmation puts to rest theories that Windows 10 will be available as a free upgrade forever. That said, current users who refuse to embrace the new operating system within the first year of its release are unlikely to ever upgrade to Windows 10 anyway, whether it's due to a desire to hold onto Windows Media Center, pure unabashed happiness with Windows 7, or any other reason.