Windows 8

With Windows 8 upgrades, Windows 8 laptops and Windows 8 tablets now having been on the market for several months, this is our definitive verdict on the full, finished Windows 8 operating system.
There are essentially two versions of Windows 8 available on the market for Intel and AMD PCs: Windows 8 and Windows 8 Pro. Windows 8 Pro is the version available as part of Microsoft's upgrade offer and from most retail stores, Windows 8 and Windows 8 Pro come pre-installed on a variety of machines.
If you want to know more about thee differences between the Windows 8 versions then read Making sense of the Windows 8 versions.

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.

If you've heard about Windows RT for ARM-based tablet devices, there isn't a version you can buy separately. It's only available on devices such as the Surface RT tablet. Check our separate Windows RT review. 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.

• Windows 8 vs Windows RT: what's the difference?

All apps in the Windows Store will run on all the different versions of Windows 8. Microsoft has even confirmed it will offer Flash functionality for IE on Windows RT.
Windows 8 doesn't include the desktop Office apps that will be bundled with Windows RT - 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 isn't available for Windows RT.

You can put Windows 8-style apps alongside the desktop

The system requirements for Windows 8 are much the same as for Windows 7, with some added requirements for Windows RT apps.
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.

The new-look desktop, 'modern UI' style features like the Settings bar and 'modern' apps all look more similar than in previews

Installing and upgrading

When you buy Windows 8 online you'll get a step by step download and installation, complete with the Windows 8 Upgrade Assistant to warn you about program and hardware compatibility issues, or you can buy a DVD.
If you're upgrading, how much of a previous Windows system you can keep when you install RTM depends on which version you're upgrading from.

Upgrade from Windows 7 and you can keep programs, Windows settings and files; upgrade from Vista and keep settings and files. Upgrading from Windows XP only gives you your personal files.
Unlike Windows 7, you can't do a full upgrade from any of the preview versions of Windows 8; you'll need to either restore your previous version of Windows from a backup, do an upgrade that only keeps your files or do a clean installation.
This option only appears with Windows 8 and Windows 8 Pro; if you have the Enterprise version, you have to upgrade from another Enterprise edition of Windows, and the previews of Windows 8 were all Windows 8 Pro, so the only option is a clean install.

Even if you have Windows 7 on your PC, you can still choose a fresh start

A button asking if you want to upgrade and keep apps, settings and files does show up when you run the installer from Release Preview, with the warning that this only works on 'supported versions of Windows' but the installer then told us that indeed, it couldn't upgrade this version of Windows and we had to close it and start over.

Looking ahead

How the PC of the future is closer than you think

Again, you won't see this if you buy Windows 8 normally, only if you're looking at the evaluation or MSDN version now.
If you're installing Windows 8 Enterprise, you activate it once it's installed (the system for that was still being set up when we started testing, so it wasn't seamless, but this is what you'll see as a normal user).
With Windows 8 Pro the installation is the same experience as you'll get if you buy a Windows 8 upgrade - it checks your system, tells you what you can keep and which programs won't be compatible (and helpfully removes them and then restarts the installation) and asks you to enter your product key as a normal part of the installation.

You don't have to restart the installation if there's an incompatible program installed

Scanning a fully loaded Windows 7 system with a lot of apps installed and many gigabytes of files takes around 10 minutes, then another hour (or on a really loaded system, two) to set up Windows 8 with all your compatible programs intact.
If you're doing a clean installation without keeping any applications, or an upgrade where you just keep files and settings, it's far faster.
On a variety of PCs it took 10-15 minutes from starting the installation and entering the licence key to get to picking the colour scheme and choosing whether to accept Express Settings or customise the setup.
One of the items under Express Settings is the controversial default of turning on the Do Not Track setting in Internet Explorer 10. Choose Customize and you can change that, but there's an ongoing argument about what Do Not Track means and how websites will treat the IE10 setting, because it is the default.
It's clearly marked and you can easily change it, but advertisers and some ad-funded organisations remain unhappy.
After this you can set up a local account or log in with a Microsoft account such as a Hotmail address, which synchronises settings with any other Windows 8 PCs you use and gives you access to the Windows Store.
While Windows 8 finishes the set up, which takes a couple more minutes, you get a brief on-screen tutorial showing you how to move your mouse into the corners of the screen to open the charm bar.
If you have a touchscreen, it also shows you how to swipe for the charm bar, but only if you have the right screen - so an older tablet PC with only an active digitiser just shows the mouse tutorial.

If you've picked a colour scheme, the tutorial uses that for the image of the screen - a little thing, but it's a subtle way of making it feel more like your PC.
Once the mini tutorial has played a few times, the set up screen starts switching between various different colours - presumably to show you the other colour choices as well as reassuring you that it's still working.
Everyone who has an account gets to see the tutorial when they first log in, making good use of the short time it takes to create the desktop the first time (they don't all get the colour show, though).
If you do an upgrade install starting with Windows running, you'll never see the option to set the language for your keyboard or settings for date and time formats. If you boot from USB to do a clean install, you're asked to choose these settings but that's it, apart from Express Settings.
In neither case do you get to choose the time zone; Windows 8 either keeps the current time zone if you do an upgrade or sets it up automatically based on the language of the installer for a clean installation.
A UK Windows 8 image kept the UK time even on a clean installation; a US image set the timezone to Pacific when we did a clean installation (you can change that quickly enough inside Windows without needing an admin account).
On a Sandy Bridge Core i5 PC with an SSD, 15 minutes after putting in the USB stick, we were running Windows 8 RTM, ready to activate and trust the PC to get settings synced from the Release Preview install setting showing up - such as SkyDrive photos and our Hotmail calendars.