We have discovered a bug that causes the Mouse Keys feature to be enabled automatically under certain circumstances when running Windows 11 version 23H2 and 24H2.
I discovered this bug by chance while checking for a mouse-related issue.
Normally, Mouse Keys is disabled (off), and to enable it you need to turn Mouse Keys on in Settings > Accessibility > Mouse.
This bug occurs when certain conditions are met, even if the Mouse Keys function is disabled (off).
Conditions under which the Mouse Keys function is enabled automatically
Currently, there are three known conditions under which the Mouse Keys function will be enabled automatically:
1. NumLock is off.
Pressing the "Num Lock" key at the top left of the numeric keypad toggles it on and off.
2. The editing screen of the Paint appActiveTo be.
Open the Paint app and click the red frame once to activate the editing screen, and the Mouse Keys function will be enabled.
In this state, you can move the mouse pointer up, down, left, and right by pressing the numeric keypad (2, 4, 6, 8 keys).
And when the Paint app editing screen is no longer active or when NumLock is turned on, the Mouse Keys function will be disabled.
3. You have installed the update for Windows 11 version 23H2 and 24H2 dated March 25, 2025 or later.
To identify the cause, I tried using an older version of the Paint app and uninstalling updates, and found that this only occurs when the following updates are installed:
Windows 11 version 23H2:
- 2025/03/25 – KB5053657
- 2025/04/08 – KB5055528
Windows 11 version 24H2:
- 2025/03/27 – KB5053656
- 2025/04/08 – KB5055523
The update from 2025/03/25 onwards includes keyboard updates, so that is likely the root cause.
- This bug does not occur on Windows 10.
- If you are checking on a Hyper-V virtual machine, you must connect using enhanced session mode.
Although it may not seem like a particularly big problem, some users have reported a bug where scrolling up and down on the settings screen is not working properly.
For example, scrolling up automatically scrolls down, or scrolling down automatically scrolls up.
The author believes that the issue he discovered this time may be related to a scrolling issue.
If you're experiencing scrolling issues, simply pressing the NumLock key once may solve the problem.
Tool to determine whether the NumLock key is on or off
I have created a tool to determine whether the NumLock key is on or off, so please feel free to use it if you need it.
Target file: "NumLockOnOrOff.exe" (Ver 1.0.0.0)
ハッシュ値(SHA256):d9b1a0c6449a0f095b3045c1e97ce4a7b418403adb5e8be85f2f07dac73a8eb7
How To Use
Download "NumLockOnOrOff.zip"Unzipand then click "NumLockOnOrOff.exe" inside.
Then,Task tray (notification area)The icon will be displayed in the (if it is not displayed, click the arrow "^" on the left)
This icon toggles to a green icon when NumLock is on and a red icon when it's off.
To exit the tool, right-click on the icon in the task tray (notification area) and click "Exit."
Comment: