Windows 10 is here. After nine months of public beta testing, the final version is rolling out to machines across the world. You can now upgrade to Windows 10 free of charge if you have Windows 7 or Windows 8.1 on your existing PC. While not every single machine will get the upgrade instantly, Microsoft is rolling out the install to millions of devices. All you have to do is register for the upgrade from the taskbar, and Microsoft will alert you once it's ready to be installed. See our guide for full Windows 10 upgrade instructions.

If you upgrade today you'll get a shiny new Start menu, built-in Xbox app with Xbox One game streaming, Cortana integration, a new Microsoft Edge browser, and a host of new built-in apps. Should you upgrade to Windows 10 or wait a little while? That and more is answered in our comprehensive Windows 10 review.