After I have completed the required procedure I have plugged microUSB to Galileo and connect to PC. this time file explorer opens directly and shows files on SD card . Galileo Gen 2 not detected on arduino IDE,. For checking , I pulled microSD card and then Galileo connect to PC this time Galileo Gen 2 detected on arduino IDE
This happened once to me, and it was because I inserted the SD card after the Galileo started (i.e. booted without the SD card). Insert the SD card before Galileo power up.
Just in case: please detail what is "the required procedure" you completed.