Mac users may claim many reasons for feeling superior to their Windows counterparts, but there is one for which some smugness is justified - backups. With Leopard's Time Machine, Apple turned the technology that normally makes you worry about such dull stuff as schedules and cycles into a tool you turned on and forgot about, safe in the knowledge that your important stuff is being saved without any further intervention.

Windows Vista, on the other hand, doesn't even include a backup option in its Home editions and, while Windows 7 will address this, Microsoft has made little attempt to update its utility for the 21st century.

So, step forward Seagate and its Replica backup 'appliance'. The box promises 'Connect, Click, Back up, Relax' and, while no mention is made of Time Machine, it's clear that this was the model for this simplified approach to saving files.

The Seagate Replica is an external hard drive that plugs into a USB port. There are two models and, while both use 5400rpm 2.5in drives inside a plastic caddy a little larger than the firm's Expansion portable drives, they serve different needs.

The Single PC model has a 250GB capacity and is intended, obviously, for use with one computer. The Multi PC has a capacity of 500GB, a stand that lets you mount the drive vertically and can be used with multiple computers, although it can only be plugged into one at once.

Installing either model is about as simple as it gets: just plug it into a USB port and run the set-up program that the Windows AutoPlay dialog box presents. Next, well, there is no 'next'. Once the brief software installation is complete, there's nothing else to do. A blue LED on the Replica pulses to show that the drive is plugged in and, if you're interested, the Replica utility in the Windows Notification Area shows when backups are in progress. You don't need to choose which files to back-up, nor specify when backups are made. It's all automatic.

For many people who wouldn't otherwise bother with backups, this black box approach works very well, but it does create a few issues.

The Replica's first backup takes some time (about an hour for 16GB of data on our PC) and there's no noticeable performance hit. Subsequent 'snapshots' are much quicker and, although Seagate doesn't say, this suggests that the Replica relies on some version of Rsync to record changes to files rather than make fresh copies each time.

By default, the Replica backs up the whole C: partition, but there's no way to exclude folders from the process. You'll need to move them to another drive if you don't want them taking up backup space. Some wastage is unavoidable though, since the Replica backs up temporary file and caches whether you want it to or not.

You can add additional partitions to the backup, but again, it's the whole partition or nothing. There's also no way to trigger a backup manually and, while the Replica is quick to detect changes, there's still a window of about a couple of minutes where files are unprotected.

As befits a foolproof backup device, restoring files with the Replica is also very simple and there are three options, depending on what you need to recover. Hover the mouse pointer over a file in Windows Explorer and a pop-up shows the number of versions saved so far, together with the time and date of the most recent. Right-click a file and the 'Seagate Replica' option on the context menu lets you open any of the saved file versions in their associated application. For files other than documents, you can opt to 'Browse in Seagate Replica', at which point a window opens with all saved versions of the file.

The Replica Browser (essentially an Explorer view of the Replica backup) can also be opened by double-clicking the icon in the Notification Area, but this isn't quite the same as that 'Browse in Seagate Replica' menu option. This just shows the most recent backup of all files, with no way to access earlier versions, and has the potential to confuse the newbies at which this device is aimed.

More troublesome still is that neither option offers a one-click restore - you need to drag (or copy and paste) the file you're recovering back to the appropriate folder on the original partition. This is hardly a chore, but it's another strange choice for such a supposedly simple backup system.

Recovering an entire C: partition means booting the PC with the supplied recovery CD. This launches a Linux environment that lets you choose a snapshot from the Replica (the most recent backup may not be the one you want to restore), before cloning it back. This worked perfectly for us and took about the same amount of time as the Replica's initial full back-up.

It's a pity that this recovery process needs a boot CD, though, as it would make more sense to boot directly from the Replica itself. Admittedly, not all PCs can boot from a USB device, but it has been a common Bios setting for some time and the option could be in addition to the boot CD.