Windows 8's Metro Start screen is the new Windows shell, relegating the old desktop to simply another application. Live Tiles show information, as well as launching applications.
Metro applications don't have any visible chrome — you'll need to open up the app bar to see buttons and controls. With Internet Explorer 10, you get a very different view of the web.
The Developer Preview comes with a suite of demonstration applications, written by Microsoft's summer interns, like this graphical weather application. Most Metro applications are either HTML or Silverlight.
Even the venerable Control Panel gets a Metro makeover, with a scrolling list controlling a view pane. Just choose the functions you need to control, and you can quickly edit them via touch or mouse.
Some Windows 8 applications are familiar, like Remote Desktop. Wrapped in a Metro skin, it's the same RDP client of old — although with added support for touch and 3D graphics. Just swipe a finger to reveal the Windows 8 'charms' to share screenshots and manage network connections.
Task Manager also gets a Metro reworking, although it still runs on the familiar Windows desktop. You can use it to track system resources, as well as controlling running applications and processes.
One of Windows 8's more interesting features is the idea of 'contracts' — API calls that link applications through Windows. You can use the Control Panel to choose the applications you want to show up in the Windows 8 'charms'.
Microsoft makes it easy to wipe or refresh Windows 8 installations. If you're having problems, a refresh will reset the OS, replacing your applications, settings and data, so you can carry on working — with only a five-minute wait.