The device functions with Leopard's Time Machine automatic backup utility. This technology allows a user to create incremental backups of files and restore a computer to a previous date, or 'look back in time' and grab a file that was inadvertently erased.

It is possible to set up a system with a Windows-based personal computer or Linux machine that recognises Apple's network-attached storage device. Sadly, the only way to determine if this will work is to set it up then trash the machine to see what happens. If you're seriously considering doing this, use some other kind of backup first. Make a copy of your applications and data in separate places.

Prices of colour laser printers are more favourable than they used to be and I know these devices perform faster than inkjet printers. Is it time for me to buy a colour laser printer? What are the potential problems? Which brand should I focus on?

Shirley, Wan Chai

DQ: I trust you know the saying, 'Beauty is in the eye of the beholder.' Well, you just jumped right into the fray. What people typically like about a laser printer is its speed, which is something we can measure and determine. Beautiful printouts, however, are a different matter.

The quality of laser printers is much better than in the past but be careful. I would never buy a printer until I see it print a page. If you like the quality it produces, it is probably the right one for you.

But fast and beautiful prints are not the whole story. You will have to buy toner cartridges over time and this is the rub. Sometimes the cheapest printer turns out to cost you the most because of these related expenses. You may want to think about how often you print: are you going to be printing in colour every day? Will you need to put it on a network? Will you need special paper to get the desired look? There is no clear winner in the brand stakes but you should visit any one of the specialist shops and scrutinise each model's printouts.

Another thing to consider is the draft mode. If you are testing a number of print jobs, you may not want to waste all that ink. The draft mode can save you a great deal until you are ready for the final print.