Why does my computer think I am holding the C key indefinitely?

Question

My computer will, at random, decide that I am holding down the C key indefinitely until I restart my computer. I have cleaned the keyboard of debris, updated drivers, deleted drivers, updated the Windows version, used the HyperX Ngenuity software to try and fix it, checked for corrupted windows system files, installed all optional drivers updates from Windows update menu. NOTHING WORKS.
There are no other devices plugged in, unplugging the keyboard does not prevent or stop this from happening. I even went so far as to physically purchase a new keyboard entirely and the issue persists. I have lost so much valuable time attempting to fix this. Every single setting on my computer is Windows 11 default save for the wallpaper on my home screen, so I have no possible idea what could be causing this.

Answer 1

Hi C,

Thanks for reaching out to Microsoft Q&A Forum. I understand that your Windows 11 PC randomly behaves as if the C key is being held down continuously, even when the keyboard is unplugged or replaced, and you would like to understand what may be causing this.

Please make sure you already tried the Q&A Assist steps. In addition, to narrow this down a bit:

1, Does the issue still occur when Windows is started in Safe Mode with Networking?

2, Does the behavior start after signing in, or can it also occur at the sign‑in screen?

In the meantime, you can try these steps:

1, Check for background input sources or software hooks

• Open Task Manager and review running processes for any keyboard, macro, RGB, overlay, or accessibility-related software
• Temporarily end any non‑Microsoft input or utility processes

2, Disable Windows accessibility features that may simulate key input

• Go to Settings, then Accessibility, then Keyboard
• Turn off Sticky Keys, Filter Keys, and Toggle Keys if any are enabled

3, Reset the keyboard input layout

• Go to Settings, then Time & Language, then Language & Region
• Remove all additional keyboard layouts and keep only one default layout

4, Run a malware and rootkit scan using Microsoft Defender

• Some low‑level malware can simulate or lock keyboard input even when no device is connected
• Use the built‑in Microsoft Defender full scan option

5, Create a new local user profile and test

• Sign in with the new profile and check whether the issue reproduces
• If the problem does not occur there, the cause is likely tied to user‑level configuration or software hooks

Also, based on your description and given that the behavior persists even with no keyboard connected and across different physical keyboards the issue is likely caused by third‑party background services, low‑level input drivers, accessibility features, or software that injects keyboard input at the OS level.

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Answer 2

Hi ,

I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.

Besides the steps provided by the Q&A Assist, perform a clean boot:

https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd

If the issue is fixed, enable the services one by one until you find the problematic services.

Answer 3

It sounds like you are experiencing a persistent issue with your keyboard where the computer erroneously detects that the C key is being held down. Since you've already tried updating drivers, using different keyboards, and checking for corrupted system files, there are a couple of additional troubleshooting steps you might consider:

1. Check for Debris: Sometimes, debris under the keys can cause keys to stick. Try using compressed air to clean around and under the keys.
2. Safe Mode: Boot your computer in Safe Mode to see if the issue persists. If it does not, a third-party application may be causing the problem.
3. Fast Startup: Disabling Fast Startup in the Control Panel has resolved similar issues for other users. This can sometimes interfere with keyboard detection at startup.
4. Registry Check: If you're comfortable, you might want to check the registry settings related to keyboard input, although this should be done with caution and a backup of the registry should be made beforehand.

If these steps do not resolve the issue, it may be worth reaching out to Microsoft support for further assistance, as it could be a deeper software issue related to Windows 11 itself.

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References:

• Why won't my keyboard work when I power up my laptop? - Microsoft Q&A
• keypad issue - Microsoft Q&A