Notice that the board came with a SD card slot, is it advisable to plug in a SD card and run optware from there rather than to plug in a old USB drive.
Screenshot on the B1-Version board
http://www.smallnetbuilder.com/cache/multithumb_thumbs/b_551_0_16777215_0___images_stories_wireless_asus_rtn66u_asus_rtn66u_board2.jpg
Screenshot on the B1-Version board
http://www.smallnetbuilder.com/cache/multithumb_thumbs/b_551_0_16777215_0___images_stories_wireless_asus_rtn66u_asus_rtn66u_board2.jpg