Error Code Portal
MicrosoftWindows Win32Error code

121

ERROR_SEM_TIMEOUT

Alternative forms: 0x00000079 · 0x79 · ERROR_SEM_TIMEOUT · 0x80070079

What does this code mean?

Code 121 · An issue reported by Windows Win32.

Official explanation · Original text

The semaphore timeout period has expired.

Troubleshooting and diagnostic links

First check that the document's product, version, and environment match your situation.

Source and terms of use

System Error Codes (0-499) (WinError.h) ↗

Creator: Microsoft and MicrosoftDocs contributors
License: Creative Commons Attribution 4.0 International
Checked on: 2026-11-12

Modifications: Extracted numeric codes, symbolic names and English message text; converted Markdown/HTML to plain text and normalized whitespace; added Korean product context, namespace labels, status classification and separately labeled official links. No machine translation of message text.

Source details · Original licenses and notices