Don't expect major changes in the beta of Windows 7 - or in the final version. The beta implements the full user interface that Microsoft was demonstrating last October, along with a few changes and improvements, but there are no major new features now and there won't be any when Windows 7 ships.

There is an in-joke in the desktop wallpaper. The Siamese fighting fish doesn't indicate that Microsoft is squaring up for battle; it's also known as the betta fish - pronounced beta.

Installing the beta takes about half an hour (after you've downloaded the files and burned a DVD) and you can upgrade from the M3 pre-beta with no problems. Microsoft is currently saying that you'll need to re-install a released version of Windows when the beta expires in August.

Windows 7 user interface

The user interface doesn't have its final look yet, but it has all the features shown before, including Aero Peek, which shows the desktop with outlines of open windows, and the new taskbar, which lets you pin icons for programs next to icons for open documents and choose the order they appear in.

There are some subtle changes to design elements. These include the cues for selecting Jump lists of common actions, previews of windows and the way the taskbar shows which apps are running and which aren't, which have been pinned so they'll stay on the taskbar and which will disappear when you close them. Rather more obvious is the Send Feedback link on every window, which makes it easy to complain about anything you find confusing - or praise anything you like, of course.

Other changes are also small and subtle. The Action Center window is a little simpler and cleaner. There's a new Content view in Explorer that gives you mini-thumbnails and document metadata at the same time. Downloads has gone back to being a folder rather than a library, because most users only access a single, local Downloads folder (although you can still create as many libraries as you want).

The Device Stage experience has changed very slightly, with a single list of options rather than two columns, but again this isn't the final look and feel. The Devices and Printers window gives you the option of automatically downloading photo-realistic icons for devices and drives; there are only a few so far. More usefully, you can right-click on any icon with a warning to run a troubleshooter, and there are now more of these - and they'll be updated automatically with any extra fixes.

Windows 7 Media Center

There are more changes to Media Center than most other areas of Windows 7, including a new Getting Started that lets you choose individual configurations if you don't want the defaults. As well as supporting gestures on touchscreens in Media Center, the beta adds more navigation options when you're using a mouse: drag the cursor along the seek bar of a video you're watching and you're supposed to get dynamic thumbnails to help you skip to the scene you want, although we didn't see this with all videos.

If you have a lot of content, as you move through lists of music and video, turbo scroll turns on automatically to jump through the alphabet rather than brining up every title individually. You can do the same with the TV Guide: keep scrolling and instead of going a program at a time, you can scroll through day by day.

Media Center also includes internet TV, in the form of several MSN channels and a desktop gadget, although this is intended to give you a taste of what's going to be possible in terms of combining online and broadcast content rather than being representative of what will be in the final version. In general, despite a clean and sleek interface, Media Center is the least polished area of Windows 7.

More to come?

The beta is feature complete; although there are "a couple of things that we're holding back", according to General Manager Mike Ybarra.

They may not stay secret until the launch as he also admits that "all of the code is in the build, just the discoverability is not." Whether someone digs out the final extras or not, what you see today is very close to what you'll get. The betta fish has brought a very dependable version of Windows, with no real surprises, good or bad.