ARDUINO NANO driver problem on WIndows 7

Anybody out there who has resolved this problem???
Help please....

Board : Nano
Recognized as "Unknown device"
When tried to update the driver .... exclamation mark does not go away.
The "COM/LPT Port" section in Device manager is not present /////
I tried all possible thing I could.

Tried "Add legacy hardware" option... and then selecting com/lpt port and pointed it to "Arduino Due Programming port"
It installed... but yellow exclamation mark present here also...

Uninstalled ...installed several times.... no effect...