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0x80070079SystemMedium

Error 0x80070079 — Semaphore Timeout (ERROR_SEM_TIMEOUT) | Windows System Error Fix

Windows 11Windows 10Windows Server 2022Windows 8.1

What Does 0x80070079 Mean?

The semaphore timeout period has expired. A network operation did not complete within the expected time.

Real-World Causes

  1. 1Slow or unstable network connection
  2. 2Server is overloaded and not responding in time
  3. 3Firewall causing connection delays
  4. 4VPN connection instability
  5. 5Large file transfer over a slow network link

Symptoms

  • ⚠Network file operations time out
  • ⚠Mapped drives become temporarily inaccessible
  • ⚠File copy operations fail after long delays
  • ⚠Print jobs to network printers fail

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Check network connectivity with 'ping servername'
  2. 2Restart your router or network switch
  3. 3Disconnect and reconnect VPN if applicable
  4. 4Try a wired connection instead of Wi-Fi

Advanced Fix

For experienced users and IT professionals

  1. 1Increase the SMB session timeout values in registry
  2. 2Check network latency with 'pathping servername'
  3. 3Disable offloading features on the network adapter

Frequently Asked Questions

Why does this happen over VPN?
VPN connections add latency and can be unstable. The default SMB timeout may be too short for VPN conditions. Try accessing fewer files simultaneously and ensure your VPN connection is stable.

Related Error Codes

0x80070039Unexpected Network Error (ERROR_UNEXP_NET_ERR)0x80070035Bad Network Path (ERROR_BAD_NETPATH)

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.