Device Driver Digital Signature Fault Is Showing Error Code 52 On Windows 7.

I am not able to view contents of my pen drive on my PC since yesterday. The contents are seen correct if the device is plugged into another machine. Every time I am getting the error code 52 on Windows 7 and showing a message that Windows is unable to verify the digital signature for the driver need for this device. .What does this mean? How should I solve this?
