Fix ERROR_NO_SIGNAL_SENT (0X000000CD) in Windows 10/11

Quick Answer

Open Command Prompt as admin and run taskkill /F /T /IM <processname>.exe to force-kill the process tree. Then restart the app.

What This Error Really Means

You're staring at a console window or a pop-up with error 0x000000CD — ERROR_NO_SIGNAL_SENT. I know this error is infuriating because it tells you something broke without telling you what. I first ran into this back in 2018 on a Windows 10 build 1803 machine running a legacy batch script. The app had spawned a bunch of child processes (like cmd.exe calling other cmd.exe instances). One of those children crashed or was terminated improperly. The parent tried to send a signal — like CTRL_C_EVENT or CTRL_BREAK_EVENT — down the process tree, but none of the remaining child processes had registered a handler for it. So Windows threw up its hands and gave you this code.

This can also happen when you close a console app with Task Manager or when a scheduled task runs a script that ends abruptly. The key point: the error is informational, not critical. Your system isn't damaged. You just have an orphaned process that won't die gracefully.

Fix Steps

1. Find the offending process. Press Ctrl+Shift+Esc to open Task Manager. Go to the Details tab. Sort by Process Name and look for any cmd.exe or conhost.exe entries with high CPU or memory. Alternatively, note the app that triggered the error.
2. Open Command Prompt as admin. Press Win+R, type cmd, then hold Ctrl+Shift and click OK. Accept the UAC prompt.
3. Kill the process tree. Let's say the process was myapp.exe. Run:
   

   taskkill /F /T /IM myapp.exe

   
   The /T flag kills all child processes too. /F forces termination. If you don't know the exact name, use:
   

   tasklist | findstr "cmd"

   
   to list all cmd.exe instances. Then grab the PID from the second column and run:
   

   taskkill /F /PID <PIDNumber>

4. Restart the application. Launch your program again. If it's a console app, run it from a fresh Command Prompt window.

When the Main Fix Doesn't Work

Sometimes taskkill itself fails with Access Denied. That happened to me on a system with a corrupted user profile. Try these alternatives:

• Use Process Explorer. Download Process Explorer from Microsoft Sysinternals. Find the stuck process, right-click it, and select Kill Process Tree. This tool can often terminate processes that taskkill can't.
• Reboot the machine. Sounds obvious, but I've seen admins spend an hour chasing this when a simple restart clears the orphaned handles. Save your work and restart.
• Check for a corrupted AppContainer. If the error appears in a Store app or a UWP process, open PowerShell as admin and run:
  

  Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

  
  Then restart the app.

How to Prevent This Going Forward

Skip the fancy registry tweaks — they won't help here. The root cause is sloppy process management in the app or script you're running. If you wrote the script, always register a signal handler using SetConsoleCtrlHandler in your code. If you didn't, check for updates from the vendor. For batch scripts, avoid using start without the /WAIT flag inside loops — that creates detached children that can orphan.

Also, don't use Task Manager to close console apps by ending the conhost.exe directly. That's like pulling the plug on a generator — sure, it stops, but the parent process doesn't know and can leave this error behind. Instead, close the console window normally or kill the parent process with taskkill.

One last thing: if this error keeps showing up for the same app, run sfc /scannow from an admin Command Prompt to check for system file corruption. Rarely, a damaged kernel32.dll can cause signal-handler lookups to fail. I've seen it exactly twice in six years, but it's worth the two-minute check.

You're not stuck with this error. Kill the tree, restart the app, and you're back in business.