I also use this adapter for Win 7 without any hassles. If drivers' update doesn't solve the issue, maybe you should try changing your adapter.

uriel wrote follow the URL above,there lists all TP_LINK antennas,including indoors,outdoors,2.4GHz,5GHz,3 to 30 dbi etc so just figure out what you want in your antennas,and choose what you need...