wireless configuration problem on sony vaio

i have a sony vaio which is about three years old and worked perfectly until recently. now i have to repeatedly manually activate the wireless zero configuration service as well as the wireless adaptor configuration. even then it continues to fall over and so i finally succumb and plug in ethernet cable - which defeats the object of wireless. i have a sky netgear router which works fine. i understand it may have something to do with the sony's own software trying to manage the wireless configuration - but cant seem to find that to disable it - if that is the right thing to do.
any help / advice greatly appreciated
thanks