look for a picture like an antenna on one of your keys - normally it is shown on one of the 'F' keys at the top of your keyboard. this picture is normally coloured differently, such as blue, and indicates you must press a function key to use it.
near your space bar you should have a key labled 'FN' or something similar. press this in conjuction with the key you found with the antenna picture on and it will switch your wireless back.
also some laptops are wireless enabled with a switch on the side of the machine.
matty, January 2010