Another key way to promote system stability with XP is to use signed driver files only. Any software or hardware that has been certified for XP will include the Designed for Windows XP logo, and will include a digital signature from Microsoft. By default, XP is configured to prompt you with a warning message any time that you attempt to install drivers that do not include this signature. However, in the spirit of compatibility, you are still given the option of using the unsigned driver, since many older applications and drivers (especially those for outdated hardware) may not have a signed version available. In general, these tend to be the same files that lead to system stability issues such as crashes, error messages, and so forth. If you receive a warning message about an unsigned driver, it’s always a good idea to check the manufacturer’s Web Site for an updated (and hopefully signed) driver.
You can control how Windows XP reacts to the attempted installation of unsigned drivers via the System applet in Control Panel. From the Hardware tab, click the Driver Signing option to control these settings. The default setting is Warn, meaning that Windows will prompt you for the action you wish to take. More risky is the Ignore option, which will always allow you to proceed with the action, and we don’t recommend this setting. The Block option will never allow unsigned drivers to be installed, but this can be a little restrictive – however, in cases where you want to stop others from wreaking havoc on your system, it’s not a bad default option, and can always be changed when necessary.