That’s the only situation where it would make sense to upgrade a Windows Vista computer to Windows 10 — and most people won’t even want to build their own PCs.
Corporations with Windows volume-licensing agreements will also get access to Windows 10, and they could upgrade their Windows Vista PCs to Windows 10 for what might be no extra licensing cost. If, somehow, you can get your hands on a cheap Windows 10 retail license, you could absolutely use it to upgrade an existing Windows Vista PC.
If you’re still using a Windows Vista-era PC, Microsoft wants to encourage you to upgrade your hardware to have a better experience with Windows 10.
In some cases, hardware may not work properly if the manufacturer fails to provide Windows 10 drivers but does provide Windows Vista drivers.
If you upgraded a Windows Vista machine to the Windows 10 preview, it’ll remain on the unstable, preview release path unless you pay for a Windows 10 license.
Want to use Windows 10 for free on a Windows Vista-era PC?
But Windows Vista and 10 have similar driver architectures — the big change was from Windows XP to Vista — so this problem shouldn’t be as common as was with the shift from Windows XP to Windows 7.
I currently have Windows Vista installed on my laptop.
Windows 7 was launched in July 2009, which means all those Windows Vista PCs out there will be six to eight years old when Windows 10 launches.
This means your old Windows Vista PCs are still getting security updates for a few more years.
They aren’t completely unsupported, like Windows XP PCs are.
Yes, if Microsoft offered Windows 10 for free — or even for a small fee — to Windows Vista computer, it would be worth the upgrade.
But, even then, you’d probably want to consider replacing that aging hardware anyway.