As long as you remove it from the old PC in the future, you can then use that license to install Windows 10 on a new PC.
Windows Vista is still under “extended support” until April 11, 2017.
If Windows 10 was free, it’d be a fine upgrade for your old Windows Vista PCs. So you have to consider whether 9 for a Windows 10 license is really worth it.
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.
Stay on the unstable, Windows Insider testing builds!
You’ll continue getting new features before everyone else — but they won’t always be stable.
If you are on Vista, you have some time before your PC becomes completely unsupported.
Want to use Windows 10 for free on a Windows Vista-era PC?
Those Windows Vista PCs are getting quite long in the tooth and lack modern processors, graphics hardware, and — most importantly — solid-state storage.
Modern computers are becoming less and less expensive.
Yes, it costs more than 9, but you’re better off putting that 9 toward some new hardware that will come with Windows 10 and saving up for a while.
If you do decide to shell out for a Windows 10 license, you’ll have to perform a clean install instead of an upgrade install. Windows won’t attempt to automatically migrate your settings and files.
If you plan on building your own computer instead of buying one that comes with Windows 10, you’ll need to buy a Windows 10 license anyway.