In computing, the Advanced Configuration and Power Interface (ACPI) specification provides an open standard for device configuration and power management by the operating system. So when your Operating System is installed there are driver that interface the OS with the ACPI functions in the BIOS. You shouldn't need to re-install the drivers for ACPI, but if you do the drivers are below.
First released in December 1996, ACPI defines platform-independent interfaces for hardware discovery, configuration, power management and monitoring. With the intention of replacing Advanced Power Management, the MultiProcessor Specification and the Plug and Play BIOS Specification, the standard brings power management under the control of the operating system (OSPM), as opposed to the previous BIOS-central system, which relied on platform-specific firmware to determine power management and configuration policy. The specification is central to Operating System-directed configuration and Power Management (OSPM), a system implementing ACPI, which removes device management responsibilities from legacy firmware interfaces.
The standard was originally developed by Intel, Microsoft and Toshiba, and was later joined by HP and Phoenix. The latest version is "Revision 5.0", which was published on 6 December 2011. As the ACPI technology gained wider adoption with many operating systems and processor architectures, the desire to improve the governance model of the specification has increased significantly. In October 2013, original developers of the ACPI standard agreed to transfer all assets to the UEFI Forum, where all future development will be taking place.
ACPI x64-based PC Driver
File: hal.inf_x86_neutral_bf3422256b0b201d.zip
3d5d69b00372673eede45a2d689caa01b53c2de5faf8f95dcff90f327be12dc8
ACPI x64-based PC Driver
File: hal.inf_amd64_67fbe41b95ca8cab.zip
6f56824207581380c277779eed1ce247598065f7a81bc77e047244d125c969a1
ACPI x64-based PC Driver
File: hal.inf_x86_4c2d3c5739eadfd0.zip
8c09db56fcdee0cb6386173a4b268cf32225e058c2b2ded88f8e2f6b225f4736
ACPI x64-based PC Driver
File: hal.inf_amd64_8555708ba4b77ef3.zip
c2de0a4b2f25521840863f97125057b9f1b54b557ff684a5437f80d1630ff373
ACPI x64-based PC Driver
File: hal.inf_x86_5a70b0277dddfb39.zip
c0c30811e7b7ccbb1930765e89866af99865ce5dfdb149ca094d2605ffe9ef11
ACPI x64-based PC Driver
File: hal.inf_amd64_neutral_232b95977cf6d84c.zip
9951ecddf7e4adcddd095164ddca59ae41ec24132fd3b4dd96618041fd7a169c