I cannot install driver of arduino UNO R3

I have used Arduino UNO R3. At this moment, I have a problem with using this Aduino board because I cannot setup the driver of this Aduino board in my OS of Window 7 SP1 32Bit.
When I tried to setup the driver, the system is alert as shown in the attached pictures:

Kindly please advise.

encounter.jpg

port.jpg

already.jpg