Carbonite

Carbonite, on the other hand, is well worth paying for. Taking the view that people are inherently lazy and don't want to pick and choose files to back up, the US-based firm charges a flat annual rate of £31 regardless of how much you back up. After initially choosing what to store, the user interface is barely needed, as the software integrates with Windows Explorer. Colour-coded dots on files keep you up to date with the backup progress, and all selected files are encrypted with a 1,024-bit Blowfish key before transfer.

Backup is continuous rather than scheduled, and you can alter the internet priority to prevent it disrupting your work. Modified files are sent after ten minutes of inactivity, but only generally once in a 24-hour period; however, you can manually force a constantly changing file to back up immediately if it's vital. Your Carbonite virtual drive appears in My Computer, letting you browse and restore individual files with ease.

That ultra-low price is per PC, and your backup is locked to the PC it was taken from, so sharing files isn't possible. But Carbonite is purely a backup service and, thanks to its set-up-and-forget convenience, it offers great value for home users.