Have a read through this thread:-
https://bitcointalk.org/index.php?topic=1173963.0It should have a vast array of answers for you. If not then post in there and someone will be able to help you.
In that thread there is a download for a specific version of cgminer which works well with the gekko. I haven't tried it on gfgminer personally but its a lot easier on cgminer as the .bat file is easier to write rather than using the different "codes" for the freq. I would suggest a mains powered hub for it and a USB Y spliter cable so you are getting enough power to it and not trying to pull too much from one port.