How to resolve error code 0x800b0100: No signature present in Windows Server 2003

Error code 0x800b0100 signifies that the certificate's subject lacks a signature. This issue can arise in Windows Server 2003 during update or service pack installations. Follow these steps to resolve it:

1. Verify the server's date and time. Incorrect date and time settings can lead to certificate issues. Ensure they are accurate.
2. Ensure the root certificate is installed on your server. Missing root certificates can cause certificate problems. Download and install the root certificate from the Microsoft website.
3. Validate the certificate. Expired or revoked certificates can cause issues. Check the certificate's validity by reviewing its details.
4. Confirm the certificate is trusted. Untrusted certificates can lead to problems. Add the certificate to your server's trusted root certificate store.
5. Ensure the certificate chain is complete. Incomplete certificate chains can cause issues. Check the certificate chain by viewing the certification path.
6. Check if the Windows Update service is active. Inactive Windows Update service can cause certificate problems. Start the service from the Services console.
7. Ensure the Cryptographic Services service is running. If not, it can cause certificate issues. Start this service from the Services console.

If the steps above don't resolve the error, reset the Windows Update components by executing the following commands in an elevated command prompt:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

These commands will halt the Windows Update, Cryptographic Services, BITS, and MSI Installer services, rename the SoftwareDistribution and catroot2 folders, and restart the services. This will reset the Windows Update components and may resolve the error.