Microsoft's Windows 8 is going to be a very big deal.

The new OS has a brand new interface, new processor support, massively improved touch features and a host of interesting new things, and it's quite dramatically different from the Windows 7 we know and love.

It's also very different from Apple'sOS X Lion, which introduced massively improved touch features and a host of interesting new things. So which one are you likely to prefer - Apple's OS, or Microsoft's? Would you be better off sticking with Windows 7? Let's find out.

Windows 8 vs Windows 7 vs OS X Lion: hardware

These days OS X is a 64-bit Intel-only affair, while Windows 7 requires 32-bit or 64-bit Intel or AMD processors. Windows 8 adds ARM support to the mix, although ARM devices will need specially compiled applications.

Actual system requirements for each OS are reasonably low: Lion wants a Core 2 Duo or better with 2GB of RAM, while Windows 7 and 8 both want a 1GHZ processor with 1GB of RAM (2GB for 64-bit).

As ever, OS X is only officially supported on Apple kit while Windows is available on all kinds of hardware, and OS X is strictly a desktop OS. Windows 7 is technically a tablet OS too, while Windows 8 has been specifically designed with tablets and touch-screen PCs in mind.

Windows 8

EVERYTHING EVERYWHERE: Windows 8 is designed to run on everything: Intel laptops, AMD desktops, ARM tablets and anything else you can think of

Windows 8 vs Windows 7 vs OS X Lion: interface

The Windows 8 interface takes a bit of getting used to, as it's a combination of the familiar Windows interface with a few big changes - especially on tablets. T

he Start menu's gone, replaced by a Start screen that resembles the Windows Phone and Kinect interfaces, and programs will be able to run in full screen mode or tiled together in a split screen view. The traditional Windows desktop will be available too, and Windows Explorer will get an Office-style ribbon interface.

We like what we've seen of Windows 8 so far, but the interface is still in development so it's too early to reach a firm conclusion on whether it works or not. There's no doubt that it's much nicer on tablets than Windows 7 is, though.

Lion is more of an evolutionary step: scrollbars have been squashed, the colour bleached out of the UI, the iOS-style LaunchPad app launcher added and a bloody horrible skin put on top of the otherwise excellent iCal, along with dozens of minor interface improvements. It's essentially a more refined version of the Snow Leopard UI - or at least, it is until you use it with a trackpad. Then it becomes a very different beast.

Windows 8

SITTING PRETTY: We love the Metro user interface, but the classic Windows desktop is there to keep old hands happy

Windows 8 vs Windows 7 vs OS X Lion: touch

Windows 8, like Lion, is all about the fingers. Forget Windows 7's faintly horrible touch features: Windows 8 is firmly finger-friendly, with a nice on-screen keyboard, gesture recognition, palm rejection - so you don't accidentally hit something if your palm touches the screen - and "fuzzy hit targeting" to work out what bit of the screen you intended to poke.

It shouldn't work, but it does: while the on-screen UI elements appear too small for touch (just like they do on Windows 7), the fuzzy targeting does a sterling job on the standard Windows controls.

For apps, however, it's up to the developers to translate the touch data. It'll be interesting to see how that works out.

Apple doesn't currently make touch-screen PCs, but Lion is still touchy-feely: it works best with a trackpad such as the ones built into MacBooks or Apple's optional Magic TrackPad, enabling you to swipe between full-screen apps, call up Mission Control to see your Spaces windows and open apps, zoom, rotate and generally fiddle around with on-screen items. The trackpad scrolling is designed to emulate iOS scrolling, which means in traditional PC terms Lion's scrolling is upside down. You can reverse that if you wish.

Windows 8

TOUCHY FEELY: The Metro interface has been designed with touching and swiping, not pointing and clicking, in mind