Windows 8 is here. With upgrades, new Windows 8 PCs and Windows RT devices now released, this is our definitive verdict on the full, finished Windows 8 operating system.
If you've been following Windows 8 through the development process, especially if you've tried the Release Preview, Windows 8 won't surprise you. The changes between the Release Preview and RTM aren't major, except possibly the removal of Aero Glass transparency from desktop windows and turning Do Not Track (DNT) on by default.
New to Windows 8?
Windows 8 represents a fundamental shift in the way Windows works and is far more touchscreen-orientated for use on tablets as well as traditional PCs. If you're completely new to Windows 8 and haven't used a preview version, we'd recommend you check out our guide to the new features you'll find in Windows 8 vs Windows 7 and Windows 8: what you'll need to relearn.
The real difference between this and previous versions is that Windows 8 is finished; it's polished and smooth, with even better performance than in the previews, and none of the rough edges left.
Confused between Windows 8 versions? Read Making sense of the Windows 8 versions
Even the previously disappointing Modern UI-style apps such as Mail, Calendar, Messaging and People are slick, sleek and far more functional.However, there is still work to do with these apps and Microsoft knows it - it released a major update to them on 10 October and several other updates subseqently.
Many of the apps are now useful and engaging rather than frustrating. This is Microsoft putting it all together.
The company has also just released a major 170MB Windows 8 update to improve performance, battery efficiency and power management.
Microsoft Windows 8 reviewThe new-look desktop, 'modern UI' style features like the Settings bar and 'modern' apps all look more similar than in previews
Running Windows 8 RTM
First of all, it's worth noting that the Windows 8 RTM is still only for x86/64 PCs; there isn't a version of Windows RT for ARM devices that you can download and try out, since there aren't any ARM devices that will run it.
That's because of the extremely custom way that ARM devices are built, where not even the way to control a physical button is standard. Microsoft isn't supporting tablets built to run Android or WebOS, either.
Microsoft Windows 8 review: You can put Modern UI apps alongside the desktop
Much of what we're seeing in the RTM will be the same on Windows RT systems as it is in Windows 8. Most features - from the Start screen user interface to the touch gestures, to the Windows desktop and built-in Windows tools such as File Explorer and Task Manager - will be practically identical (although we don't have a definitive list of which built-in tools will be built in with Windows RT).
The vast majority of apps in the Windows Store will run on both. Microsoft has even confirmed it will offer Flash functionality for IE on Windows RT (at least on what it calls the "initial delivery of Windows RT PCs").
But until we see it in action, we don't know what Windows RT performance and battery life will be like (although the promised battery life for Connected Standby and HD video playback looks impressive, at up to 409 and 13 hours, respectively).
Microsoft Windows 8 review
Windows 8 doesn't include the desktop Office apps that will be bundled with Windows RT either - although you can still install the Office 2013 Customer Preview - and of course it runs all the x86 desktop apps that won't work on RT. It also has the optional Windows Media Center, which we don't expect to be available for Windows RT.
Along with the final release, we have the final system requirements for Windows 8; much the same as for Windows 7, with some added requirements for WinRT apps.
Read: Windows 8 tablets release date, specs and prices
You need a 1GHz or faster CPU (it also needs to support PAE or PAE-NX Physical Address Extension for new security features in the Windows 8 kernel), 1GB of RAM (or 2GB for 64-bit systems), 20GB of hard drive space and a DirectX 9 graphics card with WDDM driver.
If you want to use the Windows Store to download WinRT apps, you need a screen resolution of at least 1024 x 768, and if you want to snap two WinRT apps side by side, that goes up to a minimum of 1366 x 768.