If you're a big Windows user with a volume agreement, there's also the Enterprise Edition that has a few extras such as a licence to run multiple virtual OS sessions on each PC (in case you have to use a previous Windows version to run a legacy app).

As someone who remembers the time when OS installers made the switch from a pile of floppies to one of those newfangled CD things, it came as no surprise to me that Vista has taken the next step and has become waaayyy too big for a CD. The choice we went for was a single DVD, though if your kit isn't up to such modern technology the alternative is a pile of five CDs.

We shouldn't really mock Microsoft in this respect, of course, since other OSes such as Linux have been shipping on piles of CDs for ages now; it has to be said, though, that the leap from one CD for Windows XP to five for Vista is rather a big one.

The installation process for Vista is dead simple. Just like all Microsoft's other operating systems you shove in the DVD, walk through the various wizards, adding your licence key along the way, and then wait for it to copy all its files.

Now, anyone who's ever installed Windows XP will know that once you've got the basic OS on the machine, you then have to install the various drivers for the bits of hardware that are installed.

Although XP offers to go and find the drivers via the web, in our experience it simply can't find them most of the time. Not so for Vista, whose driver finder was successful for all the built-in hardware in our Dell Latitude, along with all but one of the stack of connected peripherals (a Canon scanner).

Once you're up and running, you get the first view of the new GUI. And it is indeed new, but Microsoft seems to have got the balance of new versus old about right.

Yes, the layout of stuff has changed, and yes, the various icons are pretty different, but you still have concepts such as the main menu at the bottom left of the screen, with options located so they're still pretty easy to find.

Much of the re-organisation is sensible, it must be said – for instance, the Mobility Center brings together options that were previously spread across multiple control panels, such as screen brightness, wireless LAN connections and battery status. And of course you still have the niceties that were added to Windows XP in Service Pack 2 such as the Windows Firewall and AV protection monitor, along with oldies such as automated software updates.

There are, of course, several new bits and bobs with Vista. Although we were using a fresh, lab-based machine and didn't need to pull our documents across from an old machine, we could if we'd wished have used the new Easy Transfer to copy files, user accounts and settings from an old system.

The wacky new Windows Aero GUI is a natty 3D way of looking at things, and may appeal to some users, and the Windows Sidebar, where you can view on-screen "gadgets" showing stuff like clocks, weather information and the like (which we're personally unlikely to use), seems a pretty blatant equivalent of Apple's "Dashboard" that came along in Mac OS 10.4.

On a more businessy front, the in-built backup tools are improved, there's the new Windows Defender (an anti-spyware package which, incidentally, is also available for Windows XP SP2), BitLocker (drive encryption), and Meeting Space (for peer-to-peer collaboration).

And of course, when you're part of an Active Directory world you can use the various neat things you may or may not be used to from Windows 2000 and XP – roaming profiles, global policies and so on.

Along with the new features, though, there's plenty that's not particularly unique to Vista. Yes, there's a new release of the .NET Framework (version 3.0) but you can run this on previous Windows releases too.

Yes, the new control panels such as the Mobility Center make life easier than in XP, but the only difference is that items are accessible from a single place instead of the user having to open three or four different control panels.

This said, Microsoft has done a lot of catching up with the times, and so the search functionality is much improved (instead of just searching your disk for files, the search function is nicely integrated so it scans contacts, emails and network-based stuff too.

The Sync Manager exists in recognition of the fact that most of us have some portable device or other that we'd like to sync with something PC-based. And the Network and Sharing Center, although it doesn't do much that you couldn't do with XP, makes it easier than before to share files without knackering your computer's security.