Windows RT has arrived and if you haven’t seen it, you will. Unlike the straightforward Windows 8 desktop operating system, it may not be what you’re expecting when you buy your Windows 8 laptop or tablet some time in the near future, so Pocket-lint is here to explain what Windows RT is.

Very quickly, Windows 8 and Windows RT are drastically different, primarily because Windows RT can run only Metro apps - the touch-friendly, very front end, tile-look face of Windows 8. But there’s plenty of good stuff that Windows RT offers that is worth knowing about. So what is Windows RT all about, what sort of tablet experience does it offer and is Windows RT something that you want over normal Windows 8? Read on and find out.

Why RT?

You may not have noticed that there is no 8 in the Windows RT name. This is because Windows RT does not offer up a full Windows 8 experience. The RT stands for Run Time - confusing, we know, but very important. So, don’t go out and buy yourself the Surface for Windows 8 Pro and expect to get just the RT, Metro-style experience.

The best way of thinking of Windows RT is as a tablet-based version of Windows Phone. It sports the same tile-based Metro UI that you get on a smartphone and doesn’t go any further than that. For those not yet familiar with it, the Metro UI is the tile-based look that Windows phone 7 runs on. It is very simple to use and easy to understand.

There is however no conventional Windows desktop and therefore no fully fledged version of many of the applications you know and love, such as Photoshop and the like. Instead you’re stuck with solely Metro Apps but with Metro versions of many programs, that may not be such a bad thing. It’s also only going to come pre-installed on hardware; you aren’t going to be able to buy Windows RT separately in a box and load it on.

ARM what?

You may have heard a lot of mention of Windows ARM support in recent months. Now we don’t want to get bogged down in exactly what ARM is, because it’s quite boring and fairly complicated. We do, however, want to explain what it does.

Essentially ARM means mobile chips. It means that Windows can run on processors manufactured by the likes of Qualcomm and Nvidia. This is more important than you might think partly because of the skills these chip manufacturers already have in the tablet area. Most can squeeze plenty of power out of hardware while keeping battery life decent enough. It also means we should be able to expect similar performance as a lot of the Android competition, although this should depend on hardware and processor speed.

What will Windows RT tablets be like?

Just as with Windows Phone, Microsoft has set out a basic specification sheet which all Windows RT tablets are going to need to run. That’s great because it should mean a similar performance level across all hardware and as close to the kind of uniform experience of the iPad as you can get, given that the hardware will be made by different manufacturers. So, fingers crossed, you should even get a decent Windows RT experience even on the cheaper tablets.

So, what will the minimum specs be? First up is a very acceptable 1366 x 768 pixel screen resolution. This should ensure movies and the like look nice enough. There’s also a 10GB minimum storage space available to play with on the tablet. The tablet must have at least a 720p resolution camera with an ambient light sensor, accelerometer, gyroscope and magnetometer also included.

Keeping up the more than decent minimum spec sheet is at least one USB 2.0 slot with Wi-Fi and Bluetooth 4.0 connectivity also as standard. Microsoft has also used a minimum number of hardware buttons for all the tablet staples. That means a power key, a Windows key, volume up and volume down and a rotation lock.

By introducing a firm hardware lock on specs and buttons, this ensures against many of the pitfalls of cheaper Android tablets and should ensure that those taking a gamble on a budget piece of RT hardware, get a decent enough experience.

Apps

Here is where we run into our first problem of understanding truly what Windows RT can do. Given that it lacks the conventional Windows desktop, the majority of its experience, like Windows Phone, will be based around apps, Metro apps.

Naturally after release the number of applications available will grow and grow, but we heard that about Windows Phone and Microsoft’s mobile OS is still lagging behind the other major players on the app front. For now, there’s certainly the likes of Netflix to enjoy as well as Metro versions of some of the core Windows apps which will come with Windows RT - things like Office, OneNote, Excel, PowerPoint and Internet Explorer 10. Everything else, according to Microsoft,  will have to exist in a Metro style version if it's going to run on Windows RT.

All apps are going to be available via the Windows Store which, like the App Store and Google Play, will be the sole outlet for apps on Windows RT. Even Barnes & Noble (a new Microsoft partner) will have to distribute an e-reader app through it. Manufacturers will be able to ship tablets with applications pre-installed, however, but these will also be subject to the strict Metro UI design rules.

When and where can I buy it?

Windows RT will ship at a separate date from Windows 8. Right now we don’t have that date, so can’t give you any sort of time scale on the new operating system’s release. All the same, we’re expecting Windows 8 at around October 2012, so it would probably make sense for RT to arrive at the same time. But with a bevvy of Windows RT devices expected to be announced before the autumn, it could well happen sooner.

At the moment the only physical hardware we have seen running Windows RT is the Microsoft Surface tablet. If you want to know more about it then check out our hands-on here. Essentially it is a Windows RT version of the Asus Transformer Prime. It comes with a dual-camera setup for Skype as well as what we presume is the minimum hardware specs listed earlier.

Devices

In the coming months you should expect to see other manufacturers’ Windows RT offerings materialise. These will in all likelihood appear from major computer makers, although nothing has been confirmed yet. Who knows, given Nokia’s Windows Phone 7 experience, the Finns might even get involved.

Like the sound of Windows RT? Let us know in the comments below ... 

Surface Tablet pictures and hands-on