Hands on: How to upgrade your hard disk

In this age of digital music, photos and video, you can never have too much storage. Unfortunately, what might have seemed like a gargantuan hard disk even a couple of years ago may now be full to the brim.

Luckily the cost per gigabyte of hard disks has fallen as our desire for larger capacities has increased. The simple solution is to buy a large new disk for your ageing system, but in practice you may run into problems.

The first and most common problem for owners of PCs more than few years old is support for disks above 137GB. It sounds crazy today, but a limitation in both Windows and the Bios of older systems prevents them from recognising disks larger than 137GB, which can cause headaches for owners looking to upgrade.

The second issue is that even if your system does support disks greater than 137GB, you may find it increasingly hard to get hold of a disk that is compatible with the connectors in your system.

Older PCs used the traditional wide 40pin parallel ATA connector for hard disks, but this is gradually being superseded by the newer Serial ATA (Sata) standard, which uses a much narrower connector and cable.

Admittedly the transition between the two connectors is taking place very gradually and there are still plenty of disks on sale with parallel ATA interfaces, but some of the newer models, not to mention the lowest priced models, may only be available with a Sata interface.

So what’s the owner of an ageing system to do? Here we’ll explain the 137GB limitation and what can be done to get around it.