0x800B0101SystemMedium

Error 0x800B0101 — Certificate Expired (CERT_E_EXPIRED) | Windows System Error Fix

Windows 11Windows 10Windows Server 2022Windows 8.1

What Does 0x800B0101 Mean?

A required certificate is not within its validity period when verifying against the current system clock.

Real-World Causes

  1. 1System clock is set to the wrong date or time
  2. 2Certificate on the file has genuinely expired
  3. 3Root certificate store is outdated
  4. 4BIOS battery failure causing clock reset

Symptoms

  • HTTPS websites show certificate errors
  • Windows Update fails with certificate error
  • Code signing verification fails
  • SSL/TLS connections fail

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Check and correct your system date and time: Settings > Time & Language
  2. 2Enable 'Set time automatically'
  3. 3Sync time manually: 'w32tm /resync'
  4. 4Replace CMOS battery if clock resets on every reboot

Advanced Fix

For experienced users and IT professionals

  1. 1Update root certificates: 'certutil -generateSSTFromWU roots.sst' then import
  2. 2Check if the certificate chain is complete
  3. 3Update the trusted root certificate store through Windows Update

Frequently Asked Questions

Why does the system clock affect certificates?
Digital certificates have a validity period (not before / not after dates). If your system clock is wrong, Windows may think a valid certificate has expired or is not yet valid. This is the most common cause of certificate errors — check your clock first.

Related Error Codes

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.