I have an Asus N550JV, and right after buying it, I installed Windows 8.1. I downloaded all the drivers from the Asus-Homepage and installed them.

My Problem: I can't activate the keyboard-backlight anymore. Usually, I have to press fn+F4 to activate it, but it doesn't work (it's the same with some other key-combinations).

I know that the backlight still works, because it is shining for a second during booting.

My Question: What kind of driver is responsible for the keyboard-backlight, and where can I find it in the device-manager?

Does anyone know which driver I need for my Laptop?

  • Make sure to install the following utilities: ASUS InstantKey Utility (V1.1.3) / ExpressCache (V1.0.100) / ATKACPI driver and hotkey-related utilities (V1.0.0030) / Keyboard Device Filter Utility (V1.0.0.5). You can get all of them from the official support page: support.asus.com/… – and31415 Jan 28 '14 at 11:16
  • @and31415 Thank you! This solved the problem :). Please post your comment as an answer, so I can accept it – maja Jan 28 '14 at 13:41


Install the latest available version of the following drivers/utilities:

  • ATKACPI driver and hotkey-related utilities (V1.0.0030)

ATK ACPI is ASUS tool key of Advanced Configuration and Power Interface.

It's the driver to make BIOS and OS communicate with each other to manage the power configuration.

Source: What's the function of the driver ATK ACPI?

  • Keyboard Device Filter Utility (V1.0.0.5)

Adds additional features to standard keyboard functions such as enabling multiple key combinations.

Source: Asus Utility and Bloatware Guide

  • ASUS InstantKey Utility (V1.1.3)

ASUS-branded programs include the Instant Key utility, which lets you assign one of 10 specific commands to the Instant Key, such as Mute, launching the Web browser, or a specific app.

Source: ASUS N56VZ-DS71 Review

  • ExpressCache (V1.0.100)

ExpressCache software, when combined with a small SanDisk SSD, will provide significant boot up and application performance increases. A high-performance SanDisk SSD drive serves as that flash-based cache, while ExpressCache manages the data across the SSD and the HDD.

Source: ExpressCache Software from SanDisk


If you would like to upgrade your OS from Win 8 to Win 8.1, please upgrade to ExpressCache version 1.0.100 or above and follow below steps to update ExpressCache:

  1. Uninstall older version of Express Cache before upgrade.
  2. Download and install newer version of Express Cache.
  3. Reboot your system.

Source: ASUSTeK Computer Inc. -Support- Drivers and Download ExpressCache

Note While ExpressCache has nothing to do with the keyboard, ASUS recommends to install latest version when upgrading from Windows 8 to Windows 8.1.

You can get all of them from the official support page by selecting Windows 8 (yes, not Windows 8.1) as operating system.

Further reading

  • Where did you get the descriptions from? I already searched for some additional information, but the official homepage doesn't add such detailed information. – maja Jan 28 '14 at 14:14
  • @maja I've updated the post. – and31415 Jan 28 '14 at 14:29
  • Perfect - just redid this myself with only the first item. It was indeed under the Windows 8 tools on the Asus support site, instead of 8.1. – brichins Apr 26 '15 at 5:54

Does hitting F4 by itself activate the backlight? I have a hunch that 8.1 or the Asus drivers are prioritising the media keys over the traditional function keys.

  • 1
    No it doesn't. And maybe I just forgot to install the missing driver/utility - there were dozens of drivers. – maja Jan 28 '14 at 7:32

Maja, after upgrading my ASUS n56vz to Windows 8.1, I installed the free version of IObit's Driver Booster, which proceeded to install, among other things, several ACPI drivers. Pressing fn + f4 turns on the keyboard back-lights, pressing fn + f3 turns them off.


My ASUS N550 uses

  • fn-F4 to brighten the keys progressively.
  • fn-F3 to dim the keys progressively.

The shortcuts work like this out of the box.

  • Correction ASUS 550 – Robert Oct 9 '14 at 21:28
  • 2
    Not an answer to the question asked, and if you'd bothered to read even two lines of the question, you'd know this is not working for the asker. Your post is bad, and you should feel bad. – HopelessN00b Oct 9 '14 at 22:15
  • The user stated: – Robert Oct 11 '14 at 2:22
  • The user stated: " My Problem: I can't activate the keyboard-backlight anymore. Usually, I have to press fn+F4 to activate it, " – Robert Oct 11 '14 at 2:24
  • But you should note in the line before that he changed the OS right after buying, and it no longer worked. I agree with @HopelessN00b this is not an answer to the question asked, and YOU didn't read the question completely. – Tyson Oct 11 '14 at 2:34

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