![adjustable brightness control software for windows 7 adjustable brightness control software for windows 7](https://matrixwarehouse.co.za/wp-content/uploads/2024/03/GPX4028TW_wr_01a.jpg)
The ACPI brightness override isn't the preferred mechanism to use for brightness control, but is included for completeness, in situations where there's no other option for brightness control. If a system does have an internal display on an internal connector type, then the first enumerated display receives the brightness control. The brightness support control override (the first bit) should only be used on a system that doesn't have an internal display on an internal connector type on any display adapter. OEMs should only define the “BrightnessControl” registry value when it's required. OEMs that would like to enable brightness control on a noninternal panel must ship their own monitor.inf (see the sample inf in this article) and set this registry value appropriately. The remaining 30 bits are reserved and must be zero.
![adjustable brightness control software for windows 7 adjustable brightness control software for windows 7](https://i.ytimg.com/vi/R3OsCjSPP6c/maxresdefault.jpg)
The second bit defines an ACPI override that forces ACPI brightness to be used.The first bit in this registry value defines the noninternal monitor brightness control support.The following figure shows the layout for this value. The Registry path is HKLM\SYSTEM\CurrentControlSet\Control\Class\ XXXX, where XXXX is for the targeted individual display. Use the "BrightnessControl" DWORD registry value. This feature also doesn't support the ability to control the individual panel brightness on multiple display panels. OEMs must still implement the hardware brightness control and integrate that with the graphics driver as they would for an integrated connector display. This feature only allows OEMs to indicate to Windows that an external connector display supports brightness control. For those configurations, Windows has the ability to designate exactly one display panel to support the system software brightness control. Some OEM systems have internal displays that are connected using external connectors such as HDMI.