Windows Home Server is a new kind of computer that can help you share music, videos and other documents when plugged into a home network.

This model, made by HP, will back up any folder from up to 10 Windows PCs on a regular basis, which is a good idea since modern hard disks fail, on average, three to five years after first use.

It's comforting to have a small box in the home with your files on it, just in case. Windows Home Server will also inform if computers connected to the network don't have up-to-date anti-virus software or the latest security updates.

The term "server" can sound daunting, but Microsoft has worked hard to make this as easy to use as any other program - you just install a piece of software called the console. Inside this, there are large icons to share files, back them up or manage a personal website on the server. The help files have a few gaps in them, but only when covering the more advanced aspects.

This home server is essentially a low-end PC that doesn't have the ability to use a monitor. It's a small and quiet device, standing just 25cm tall and 14cm wide. As a PC it would fare poorly against competitors, but it was faster than any other network hard disk we've tested, backing up 100GB of files in 40 minutes.

The Mediasmart EX470 (its full name) comes with a 500GB hard disk as standard, and three spare bays for future storage. Each bay, which can take one extra disk, has a light next to it that shines blue when a disk is present, or purple when it's empty. If two disks are used data can be backed up on both so that if one fails, the shared folders can still be recovered.

Four USB ports and an eSata port on the back can be used to add external hard disk and USB keys, but do beware: hard disks and USB keys are wiped automatically when they are first plugged in.

The device will stream video, music and photos to an Xbox 360 if you have one, or a network media streamer, so you can conveniently watch in the living room video stored on a PC elsewhere. There is also an iTunes server, which picks up all the music from PCs with iTunes installed and shares it out.

HP has also provided something called Photo Webshare, which allows users to set up photo galleries on their own website (which it sets up for you). Friends and family can then view from anywhere, although having it's important to have a decent broadband connection because they'll be reading them right off the home server.

The real beauty of Windows Home Server lies in the extra "add-ins" that can be installed. These utilities can do many things including remotely switching on and off computers on the network, but because they're not made by known manufacturers they can be tricky to install.

Power consumption was higher than other network hard disks - we estimate annual energy bills of £39 for the Mediasmart EX470. These niggles, and the £400 price tag, mean it's only suited to those who enjoy tinkering with add-ins and need top performance from a backup device. More Home Server devices are on the way from other manufacturers but this sets the bar high.

Vista compatibility: Yes