What does Windows error code 722 (ERROR_TIMER_RESUME_IGNORED) mean?

ERROR_TIMER_RESUME_IGNORED

A timer API ignored its resumable or wake-capable flag

ERROR_TIMER_RESUME_IGNORED corresponds to Win32 error value documented as: The resumable flag to a timer API was ignored. The requested timer was created or set, but Windows could not honor the option intended to resume the machine. The timer may still fire while the system is awake, so callers must distinguish partial behavior from total failure.

Where the result appears in real systems

• Scheduled maintenance tasks.
• Backup programs asking to wake a sleeping computer.
• Power-management utilities using waitable timers.

What to collect before making changes

Record timer due time, period, flags, OS edition, sleep capabilities, and current power policy; query supported sleep states; test whether firmware and administrative policy permit wake timers.

Handling and recovery

Continue only if an ordinary non-waking timer is acceptable. Otherwise notify the user or scheduler that wake cannot be guaranteed and provide a policy or firmware remediation path.

What not to infer from this code

This result is not the same as timer creation failure. The timer object can exist even though its resume semantics were rejected.

References

• Microsoft: System error codes 500–999