If the side buttons on your Corsair mouse are not working, you need to assign them tasks through iCUE, reset the mouse or update its firmware. Unlike conventional computer mice, the various Corsair gaming mice have additional buttons on their sides, labeled 1,2, 3, and so on. 

The side buttons may be configured to accomplish different functions in-game. However, the buttons may fail to work as expected. Only two of the side buttons are configured to work right out of the box. For the others to be usable, you first need to assign them tasks through the Corsair Utility Engine (iCUE).

The Corsair mouse side buttons not working may also be caused by corrupted or outdated drivers on the computer. Throughout this guide, you will learn what causes this malfunction and how you can fix the problem on your own. 

What causes Corsair Side Buttons Not to Work? 

If the side buttons are not working, it is possible that the computer is not recognizing them or no default action has been assigned to them. Discussed below are some of the common causes of the Corsair mouse side buttons not working issue: 

No Action is Assigned to the Buttons 

This is, by far, the leading cause of the side buttons not working issue on different Corsair mice models. The various gaming mice by this manufacturer offer several other buttons, beyond the conventional right and left mouse buttons.

These buttons need to be present with useful functions for easy and quick navigation in-game. You can configure these buttons to your specific needs and preferences through the Corsair Utility Engine. 

To bind the additional side buttons on your mouse to in-game controls, you should use the Remap Key feature, as elaborated later in this guide. 

Expired/Outdated Mouse Drivers 

If the Corsair mouse drivers on your computer are outdated or corrupted, they may cause the mouse to malfunction. In such a case, the computer could fail to recognize some or all of the side keys on your Corsair mouse. In this case, the iCUE software could be corrupted or outdated. 

In either case, you need to update the affected software. Alternatively, you could just uninstall and reinstall the drivers afresh. 

How To Solve This Issue?

The appropriate solution to the Corsair mouse side buttons not working issue will mainly depend on what you would like to use the buttons for. While the mouse is specifically designed for gaming applications, it may also be used within the operating system. 

In this regard, only the left-click and right-click buttons (buttons 1 and 2) come preconfigured to work by default. This being the case, all the side keys will not work in the operating system right out of the box. For gaming applications, different kernel-level drivers allow for USB device input and will recognize up to five mouse buttons—right click, left click, scroll wheel, and button as well as side buttons 1 and 2. 

To troubleshoot the issue, you first need to check whether the right click, left click and scroll buttons on your mouse are working. If they are not working, the entire mouse has a problem. If these are working, then you can use the following methods to fix the malfunctioning side keys: 

Method 1: Unplug then Plug the Mouse Back In 

An error j connection, especially for the wired Corsair mice can cause the computer not to recognize the mouse or some buttons on the mouse. Before trying the more advanced solutions, you should just unplug and plug the mouse back into the computer. 

To do this, you need to unplug the wired Corsair gaming mouse from the computer, and then reboot the computer with the mouse unplugged. Once the computer has booted, plug the mouse into a USB port on the computer. Allow the computer enough time to load the mouse drivers and then check whether the problem has been fixed. 

Plugging the Mouse into a different USB port on your computer may also help. 

Method 2: Assign the Side Buttons Through iCUE 

If you just purchased the mouse, the side buttons will not work until you assign them a task using the Corsair Utility Engine. To bind the side buttons on your Corsair gaming mouse to various in-game controls, you need to use the Remap Key function. 

Here is how you should go about it:

Step 1: First, you need to download and install the iCUE software into your computer, if you have not done it already. 

Step 2: Launch iCUE on your desktop and navigate to the Home menu. You should then click on Devices and then select the mouse you would like to configure from the list of devices displayed. 

Step 3: Now click on the ‘Actions menu’ on the left-hand side of the window to expand it. 

Step 4: From the Actions menu, click on the + button, expand the center drop-down menu, and then change from ‘MACRO’ to ‘A-Z KEYS’ (under the REMAP section). 

Step 5: Click on the circle adjacent to ‘P’, and then on the Back button to the left of the mouse image. 

If all went well, you should have a new action named ‘Remap A-Z Keys #’. To test your configuration, just click on the search bar in the Actions menu. Now click on the Back button, it should type ‘P’ into the field. You can now visit the Controls menu within your game and bid whatever control you would like the P key to accomplish. 

Method 3: Reset the Corsair Gaming Mouse 

If the side buttons on your Corsair gaming mouse are already configured, but not responsive, you should consider resetting the mouse. The right procedure for resetting a Corsair gaming mouse will depend on the mouse type, as described below:

How to Reset a Wireless Corsair Mouse 

If you are using a wireless Corsair gaming mouse, regardless of the model, you should first turn the mouse Off. Next, press the right and left mouse buttons simultaneously and hold them down. While holding the left and right mouse buttons, you need to power the mouse back On and continue holding the buttons down for another 5 seconds. 

After 5 seconds, release the left and right buttons. If the mouse reset successfully, you should see an LED flash. 

How to Reset a Wired Corsair Mouse 

The resetting option in the various wired Corsair mice models allows you to fix such issues as repeating button inputs, side buttons not working, and lighting issues. Note that the procedure for resetting the Scimitar Pro RGB differed slightly from the procedure for resetting the Dark Core RGB/SE mouse. 

To reset a wired Corsair gaming mouse, unplug it from the computer then press and hold the right and left buttons. While holding the left and right mouse buttons down, plug the mouse into a USB port on your computer. Continue holding the left and right buttons down for about 5 seconds and then release them.

The LED light on the mouse will flash to tell you that the mouse reset successfully. 

How to Reset the Scimitar Pro RG

Unplug the mouse from the computer, then press and hold the left and right buttons. While still holding these buttons, plug the mouse into a USB port on your computer. Continue holding the left and right mouse buttons down until the LED lights on the mouse begin to flash. 

At this point, you need to release the right and left mouse buttons. Finally, you need to unplug the mouse and then plug it back in. 

How to Reset the Dark Core RGB/SE Mouse 

Turn the Power switch at the bottom of the mouse to the Off position. Next, press and hold down the Back and Forward side buttons on your mouse. While still pressing these buttons, turn the Power switch back to the ON position. 

Method 4: Update the iCUE Software 

Launch your preferred browser on your desktop and then navigate to the Corsair Software downloads page. Find the latest iCUE software installer file that is compatible with your computer and download it to your computer. 

Next, open the downloads folder on your computer and double-click on the executable iCUE file you just downloaded. This operation will launch the Installation Wizard on your computer. Now follow the on-screen prompts to complete the installation process. 

Once done, close the installation wizard and restart the computer. Check whether the Corsair side buttons not working issue has been resolved. 

Method 5: Update Your Mouse Firmware 

If the Corsair mouse side buttons are still unresponsive, you should consider updating the mouse firmware on your computer. This can be accomplished using the Corsair Utility Engine. Ensure that the computer is connected to the internet and that the problematic mouse is connected directly to the computer. 

You should then launch the iCUE program on your desktop and click on Settings. Next, select the problematic mouse from the Settings menu and click on the Update button. Select how you would like to update the firmware from the next screen. 

Choose the ‘Force update’ option and click next. Now select the Firmware Image to use the downloaded firmware update file. You can also use this option to roll back to a previous firmware version that worked. The computer will automatically update or roll-back your firmware as directed. 

Final Verdict 

Ranging from corrupted firmware to outdated Corsair Utility Engine software, different things can cause the side buttons on your mouse not to work. On rare occasions, unplugging, restarting the computer, and then plugging the mouse back solves the problem. 

In other cases, you need to update the mouse firmware, and iCUE software or even reset the Corsair mouse to fix the issue. Regardless of the case, this guide will help you resolve the Corsair side buttons not working issue.