How does setting the Plug-and-Play (PnP) option in a PC's BIOS to No/Disabled affect my system?
For x86-based systems, the way the BIOS interacts with PnP devices can vary, depending on whether the BIOS or the OS is responsible for configuring the hardware.
- For a fully compliant Advanced Configuration and Power Interface (ACPI) OS, such as Windows XP, the OS assigns device resources and ignores BIOS settings. This includes reassigning IRQ, DMA, and IO resources as well as arbitrating conflicts for all PCI devices. Because the PnP BIOS setting is ignored and ACPI is used instead, the BIOS setting can be left at either Yes/Enabled or No/Disabled, although Microsoft recommends that you set the option to No/Disabled.
- For a non-compliant ACPI OS, the BIOS assigns device resources prior to the loading of the operating systems, and the PnP BIOS setting must be No/Disabled.
- For a non-ACPI OS, the BIOS assigns device resources prior to the loading of the operating system, and the PnP BIOS setting must be No/Disabled.
- For a multi-boot system, this is especially important. In this case, the PnP BIOS settings must be No/Disabled. Otherwise, the system check for PnP may pass on one OS but fail on another OS.
In summary, the PnP BIOS setting should be set to No/Disabled. Because this setting only controls what system component is responsible for resource allocation, it will have little impact on the system's behavior and performance.