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0x800B0100SystemHigh

Error 0x800B0100 — No Signature (TRUST_E_NOSIGNATURE) | Windows System Error Fix

Windows 11Windows 10Windows Server 2022Windows 8.1

What Does 0x800B0100 Mean?

No signature was present in the subject. The file does not have a digital signature.

Real-World Causes

  1. 1Windows Update file was downloaded without its digital signature
  2. 2File was modified after signing, invalidating the signature
  3. 3Update catalog or cab file is corrupted
  4. 4Man-in-the-middle attack stripping signatures

Symptoms

  • ⚠Windows Update fails with signature verification error
  • ⚠Cannot install unsigned drivers
  • ⚠Downloaded updates fail integrity checks
  • ⚠Security warnings about unsigned files

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Run Windows Update Troubleshooter
  2. 2Clear Windows Update cache and re-download updates
  3. 3Re-download the file from the official source
  4. 4Run 'sfc /scannow' to repair system catalog files

Advanced Fix

For experienced users and IT professionals

  1. 1Reset the cryptographic services: rename catroot2 folder after stopping cryptsvc
  2. 2Check system time is correct — certificate validation fails with wrong time
  3. 3Re-register crypto DLLs: 'regsvr32 wintrust.dll' and 'regsvr32 softpub.dll'

Frequently Asked Questions

Is it safe to bypass signature checks?
Generally no. Digital signatures verify that files came from the expected publisher and have not been tampered with. Bypassing these checks opens your system to malware. Only do so for trusted drivers in test environments.

Related Error Codes

0x800B0101Certificate Expired (CERT_E_EXPIRED)0x800B0109Untrusted Root (CERT_E_UNTRUSTEDROOT)

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.