If you have a computer that is running Windows 7 or Windows Server 2008 R2 and you install a driver that has a Windows Hardware Quality Labs (WHQL) or Authenticode signature on the computer.

But in Device Manager, when you expand the corresponding device, right-click the driver, and then click Properties and then click the Driver Details button on the Driver tab, you may find that the driver file is displayed as unsigned!

This issue occurs because of incorrect logic when the Authenticode flag in the catalog file of the driver is checked.

To fix this issue download and apply this hotfix from KB2619914.