Event ID 4740: A user account was locked out

Windows Event ID Lookup: What Windows event IDs mean: 4625, 4624, 4740, 6008, 41, 7045, 1102 and 3,000 more, with Windows' own message text, the fields and what to check.

Look up a Windows event ID from Event Viewer, a SIEM alert or a log export: what it means, the fields it records, and what to check. Many IDs are used by more than one source (event 41 is both a Kernel-Power crash and a boot error), so every definition is shown, the one people usually mean first. The message text is Windows' own, read from the event providers of Windows 10.0.26200.0, 2026-10-28; the notes are ours, based on Microsoft's security auditing reference.

Try: 4625, 4624, 4740, 6008, 41, 1074, 7045, 1102, 4104, 1149

A user account was locked out.

Event 4740

Security-Auditing

Security log

Audit Success

A user account was locked out after too many bad passwords. Logged on the domain controller that processed the lockout (the PDC emulator sees them all).

What to check: Caller Computer Name is where the bad passwords came from: often a phone, a mapped drive or a service with an old saved password. Unlock with 4767 once the source is fixed.

Related: 4625, 4771, 4767

Message and fields (as Event Viewer shows them)

A user account was locked out.

Subject:
	Security ID:		…
	Account Name:		…
	Account Domain:		…
	Logon ID:		…

Account That Was Locked Out:
	Security ID:		…
	Account Name:		…

Additional Information:
	Caller Computer Name:	…