What are signed drivers?
The signed drivers are device drivers that include a digital signature, which is an electronic security mark that can indicate the publisher of the software and information that can show if a driver has been altered. When Microsoft signs it, the driver has been thoroughly tested to make sure that the driver will not cause problems with the system’s reliability and not cause a security problem.
Drivers that are included on the Windows installation DVD or downloaded from Microsoft’s update Web site are digitally signed. A driver that lacks a valid digital signature, or was altered after it was signed, cannot be installed on 64-bit versions of Windows. If you have problems with a device driver, you should download only drivers that are from Microsoft’s update Web site or the manufacturer’s Web site.
Windows was designed to work with a large array of devices. Unfortunately, in the past, there were times when a device was added and a driver was loaded, the driver caused problems with Windows. As a result, Microsoft started using signed drivers to help fight faulty drivers. Although signed drivers will not fix a faulty driver, they make sure the publisher of the driver is identified, the driver has not been altered, and the driver has been thoroughly tested to be reliable so that it will not cause a security problem.
Note: You cannot install a driver that lacks a valid digital signature or that has been altered after it was signed on Windows Server 2008 R2.
Windows Server 2008 R2 is delivered only in 64-bit versions; all drivers must be signed for Windows Server 2008. If you are using a newer version of Windows that is not a 64-bit version, you can use the File Signature Verification program (Sigverif.exe) to check whether unsigned device drivers are in the system area of a computer.