Making sense of the Windows 8 versions

With only two versions of Windows 8 to be available to consumers, plus one for ARM devices, what you get ought to be straightforward.

But, as is usual with a new version of Windows, there's nevertheless room for confusion because what you get with each version overlaps slightly.

The home version for x86 Intel

Windows 8 is the home version for x86 Intel and AMD PCs. The features you do and don't get as a rule make sense; joining a domain, encrypting your disk with BitLocker and being able to log into your PC remotely are business features.

You can connect to a PC at work from a Windows 8 system, with Remote Desktop or a VPN, you can combine multiple hard drives into one storage 'pool' that has multiple copies of your files and you can mount VHD and ISO images as if they were hard drives – however you can't boot from a VHD file.

And anyone who speaks more than one language or travels between countries will be delighted that you can switch not just the keyboard nevertheless the Windows interface from one language to another without paying extra.

What doesn't suddenly make as much sense is that not only is Media Center not included with Windows 8; it's "an economical media pack add-on" that's only available for Windows 8 Pro, which is if not for business users. Again it's for for x86 Intel and AMD PCs.

Although Media Center has dedicated fans, only 6% of Windows 7 users ever launch it and only 25% of those use it for more than ten minutes at a time.

The codecs used in Media Centre

Microsoft has to pay licences for the codecs used in Media Centre, including Dolby innovation. When the Developer Preview came out last September, Sinofsky commented that "the feedback about Media Center was predominantly "we will pay extra, just include it" based on the input directly to me," so it looks like Microsoft is taking users at their word.

All three versions of Windows 8 run Metro-style applications written in WinRT, the new Windows RunTime programming framework, which is as well what Windows RT is named for. Windows RT will come pre-installed on ARM devices, you won't be able to install it yourself.

What we've earlier been calling Windows on ARM

This is what we've earlier been calling Windows on ARM. It has both the Metro Start screen and the Windows desktop, with Task Manager and Explorer and support for multiple monitors.

But although you get the desktop on Windows RT, you can't install desktop applications. It comes with ARM-specific versions of Office apps – nevertheless just Word, Excel, PowerPoint and OneNote, so if you want Outlook you need a PC with an Intel or AMD processor.

Windows RT doesn't include Media Center, or Windows Media Player; it will have updated version of the Music and Video apps we've seen for the Consumer Preview.

It doesn't have BitLocker, nevertheless it does have its own form of device encryption, which is based on a Trusted Platform Module like BitLocker. That's not the same hardware TPM you find in Intel PCs today, it's part of the firmware in the system, yet that's the same way that System on Chip x86 PCs running Windows 8 will implement the TPM, to keep power and hardware costs down.

The main difference between device encryption

The main difference between device encryption and BitLocker seems to be that BitLocker can be managed by an IT administrator in a business using group policies and a domain; with no group policies or domain support that won't work on Windows RT. If you can manage device encryption it will be through Exchange Active Sync – the way you sync email and calendar appointments – which can already make you use a strong password on a smartphone or a Windows 8 PC.

Running desktop apps on a tablet would be a bad idea. Though there will be Ultrabook-style thin notebooks running Windows RT in other words than just tablets, tablets with just a touch screen aren't the best way to use the tiny icons and toolbars of the average Windows program.

ARM processor they'd be slow

Even if you could run x86 instructions virtually on an ARM processor they'd be slow, and with all the background services and startup apps and power-hogging tools built into Windows app, they'd run down your battery.

But if you want a thin, light, low power Windows 8 tablet that does run desktop applications, that's on the whole on the cards using low-power System on Chip processors from Intel and AMD.

Like ARM-based Windows RT devices, Windows 8 PCs with x86 chips can give as well you Connected Standby.

Connected Standby needs specific hardware that's not available but, including Wi-Fi and mobile broadband hardware that can stay awake during the system is asleep, and a new level of ACPI power settings as then a new version of the NDIS network interface standard.

And during any Windows 8 or Windows 8 Pro PC can have Connected Standby according to Microsoft's feature list, it's only going to be low-power SoCs that can meet the requirement for only using 5% of battery if you leave them on Connected Standby for 16 hours overnight.

The best of both Windows 8

If you want the best of both Windows 8 and Windows RT, SoC PCs will give you that. However running Windows apps as well means they need antivirus software and they'll come with all the crapware OEMs like to 'enhance' their PCs with; Windows RT tablets might come with extra Metro apps form OEMs yet they'll be easy to remove and they can't run in the background.

When you come to pick a Windows 8 PC, you'll have to weight up compatibility versus losing some of the deadweight of the Windows environment. That's what the different versions of Windows 8 are in effect about.