The last (or first, in some BIOS menus) area is the most arcane, but also the most intriguing, most powerful, and potentially most dangerous of all. It goes by many names, but we'll call it the Frequency/Voltage Control screen. Here, the overclockers come and play, tweaking voltages and memory and CPU speeds in search of performance gains (or at least bragging rights).

Many times, the initial or factory settings of a PC are rather conservative, and if you know your hardware, resetting them to take full advantage of installed components -- for instance, running DDR333 or PC2700 memory at 333MHz rather than 266MHz -- can yield a noticeable speed boost. For others, it's a matter of ripping up the warranty and jacking processor speeds to the maximum, such as turning a 1.8GHz CPU into a 2.4GHz screamer with a few basic adjustments.

Again, this section is deadly dangerous for inexperienced users, and we recommend further research -- beyond the scope of this introductory article -- into the various settings and the interdependencies between them. For example, raising the CPU clock speed usually requires an increase to the core voltage, which in turn results in higher processor and system heat levels. An incorrect or overly ambitious setting can result in system instability, corrupt data, or permanent hardware damage, so plan before you play, and even then, tread lightly.

Upgrading the BIOS

Ancient PCs kept their BIOS firmware in ROM chips that had to be physically removed and replaced for a new version, but current systems use flash EEPROM (electrically erasable programmable read-only memory) that can be upgraded by running a software utility.

Depending on the manufacturer, there are several methods used to perform a flash BIOS update, ranging from the trusty DOS boot disk to sophisticated Windows utilities and neophyte-oriented update Web sites. The last one is sort of worrisome (i.e., carrier dropped in the middle of an update); with the release of Windows XP, most vendors have moved to a graphical interface where the program confirms the update and loads the new BIOS file seamlessly.

Even with today's much safer methods, a BIOS update is not without risk; a power outage or data corruption can lead straight to a Return Materials Authorization call to your dealer. Motherboard and BIOS vendors usually post firmware updates to support new hardware or fix bugs in very specific configurations; if you don't require a BIOS update, then don't install it. It's as simple as that.