firstly, DO NOT turn off your computer in the middle of an update, especially a long one (possibly a service pack update). Second what OS are you using? Im going to assume XP, jej was correct in suggesting a system restore to the point before the update. You could also try rolling back the wireless network card driver by right clicking my computer, select properties, hardware tab, then device manager. go to network adapters, click on it to show adapters then right click on your wireless network card and select properties. Click the driver tab and lastly Roll Back Driver. this should give you your wifi access back, rerun updates and do not interrupt them.