Microsoft Windows Update Errors

Error Messages
You may see a number of error messages when your computer is unable to perform an update. The first may say 'Digital Signature Not Found.' This means the update you are trying to download does not contain a Microsoft signature, and may not work with Windows. You may also see a number of error messages which refer to the Cryptographic Services.
Causes
Many things may be causing the error. For example, the wrong download policy may be set. This means you've selected 'Do Not Allow Installation' when the package doesn't possess a digital signature. Additionally, other necessary files may be corrupt or missing, or you may need to enable Cryptographic Services.
Cryptographic Services Fix
You can set Cryptographic Services to automatic by clicking the 'Start' icon, then clicking 'Control Panel' and then 'Administrative Tools.' Click 'Services,' then right-click 'Cryptographic Services.' Choose 'Properties' and change the 'Startup Type' to Automatic. Click 'Start.'
Allow Installation
Try running the update again. The update will warn you that the package does not have a digital signature. It will then ask you if you want to proceed with the installation. Click 'Yes' and allow it to download. If these suggestions do not fix the problem, consider taking the computer to a professional.