A driver is a program that controls or helps operate a hardware device. When 3rd party vendors create a new driver, it can be submitted to Microsoft for “device signing“. This ensure quality. To help maintain the integrity of your Windows 8, critical files are digitally signed so that any changes to these may be easily detected. However not all drivers are digitally signed, as a result of which some of them may cause system instability.
Microsoft has a tool in place in Windows 8/7 and Vista called Sigverif.exe which helps you identify unsigned drivers.
To access it, type sigverif in Windows start menu search box and hit enter.
Click Start. The program scan all the device drivers.
On completion of the scan, it will list down those which are not digitally signed. In my case it turned out to be an Acronis file.
Should you wish to see the list of all the drivers scanned, Click on Advanced & select View Log.
You will be able to view the log.
To verify if your Drivers are digitally signed, you can run the DirectX Diagnostic Tool. To do so, type DxDiag.exe in the Start Search Box and hit Enter. The DirectX Diagnostic Tool is designed to help you troubleshoot DirectX-related issues.
The DirectX Diagnostic tool (DXDiag.exe) gathers information about the system and the DirectX installed components. It also provides a number of tests to ensure that components are working properly. Use the diagnostic tool to create a report about your computer by running Dxdiag.exe and clicking on the Save All Information button.