HP Smart Install is a service running on firmware which makes printer to appear as "Mass Storage Devices" when connected via USB cable. This is to install the minimal printer software from flash memory of printer. This service needs to be disabled on Windows in order to have the device function as a printer.
You can detect and disable Smart Install using the below methods:
1. Using Device Front Panel. (Solved my problem)
Settings->Services->HP Smart install
you may look in 2 places :
-control panel>power options
-device manager >USB controllers>Generic USB hub; select it's properties, power management tab and disable "the computer can power off the device to save energy
Change the below registry value in windows 7 machine.
Find the offending printer entry, then find the entry named.
Edit it. Changing it to the value of 1