ERROR_TOO_MANY_SEMAPHORES 0x80070064

Error code 100 · HRESULT 0x80070064

WINDOWS

Cannot create another system semaphore.

Windows troubleshooting diagram: Device Manager warning and a system file scan
Windows errors: check drivers, system files and Event Viewer, in that order.

What it means

ERROR_TOO_MANY_SEMAPHORES is a Windows error code (system error 100, returned as HRESULT 0x80070064) reported by Windows. Its official message is: “Cannot create another system semaphore.”

How to fix ERROR_TOO_MANY_SEMAPHORES

  1. Reboot once — many one-off system codes disappear with a clean restart
  2. Repair system files: 'sfc /scannow' then 'DISM /Online /Cleanup-Image /RestoreHealth'
  3. Find the source in Event Viewer → System: filter for this exact code and open its provider link

Related errors

ERROR_TOO_MANY_SEM_REQUESTSERROR_TOO_MANY_SESSERROR_TOO_MANY_NAMESERROR_TOO_MANY_CMDSERROR_INVALID_PARAMETERERROR_EXCL_SEM_ALREADY_OWNEDERROR_SEM_IS_SET

Source: Microsoft WinError.h

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