Hardware Tips: Tweak Your PC's BIOS Settings the Safe Way

First, Do No Harm

When working with your PC's Setup utility, use the same rule of thumb taught to budding brain surgeons: If you don't know what something does, don't mess with it. Inadvertently changing a wait state or other cryptic setting can slow performance or even cause a system crash.

If you think you may have accidentally changed a setting while working in the Setup utility, play it safe and start over. All Setup utilities have a menu choice that lets you exit without saving changes. You may also see a choice for returning the settings to their default values. Ignore this option: If your PC's vendor fine-tuned the system, the BIOS maker's default settings may not be optimal.

Back up your settings before making changes. When the battery that powers the clock/calendar chip dies, your settings die with it. If your Setup utility has a backup option, use it. If not, write your settings down on paper--or press the Print Screen key for each screen in the utility (this doesn't always work, however).

What to Look For

Before you start, read through the user manual that came with your PC or motherboard. Many manuals offer a short explanation of each setting. Settings vary by manufacturer and model, but you should find these on almost all PCs:

Optimization and compatibility settings: The Setup utility often contains settings for hardware performance. Sometimes these aren't set optimally at the factory, especially on generic or built-to-order PCs. Scan the entire Setup program. AGP mode settings and DMA settings are good candidates for optimization. These settings are also useful for troubleshooting newly installed hardware: Disabling or lowering a given setting may kick-start a heretofore incompatible graphics card, CD-ROM drive, or other device.

Hard-disk settings: You'll find a table, usually on a second or Advanced page and with "IDE" in its title, that lists all the configuration parameters for the EIDE hard drives directly connected to your motherboard. (SCSI hard drives and EIDE hard drives running off an expansion card will have their own configuration programs.) While most PCs made in the last few years can seamlessly detect and configure new hard disks, some require manual installation. Read your new disk's documentation on that procedure and use the on-screen options ( FIGURE 1 shows an example) to make changes in this table.

Floppy disk: This option lets you set the type of floppy drive (3.5-inch, 1.44MB, for instance) that you have designated as your A: or B: drive. This is a good setting to check if you're having floppy-drive problems. Some Setup utilities have a separate 'Floppy Read only' security setting that prevents your data from being written to a floppy disk and removed from the PC.

Boot sequence: This setting determines where the PC first looks for boot-up instructions. For example: 'A: then C:', 'C: then A:', or 'C:, Zip drive'. To boot from a CD-ROM, Zip, or LS-120 drive, you'll likely have to change this setting.

Password protection: If this is enabled, the BIOS will ask for a password before booting up. Be very careful with this one: If you forget the password, you'll have to reset a motherboard jumper or disconnect your CMOS battery, which will cause you to lose all your settings, or you may even have to buy a new motherboard.

IRQ settings: If you need an extra IRQ setting for new hardware, you may free one up by disabling an unused feature, such as a serial port, parallel port, or USB port.

Parallel port settings: Select the mode that works best for your hardware. ECP or EPP modes can speed up printers and other devices considerably (see FIGURE 2).

Fan RPM and CPU temperature: These two critical parameters should be checked periodically to ensure they are functioning properly.