Hi

Have you accidendtly switched the wireless off ??? you may of pressed it by mistake and disabled have a look around on the side the front or on or around the key board there should be a tab or slide switch with a picture on or beside it that looks a bit like a satallite depending whether its a slide or push swith try to activate it by pressing it or sliding it and holding in place for a few seconds

on some laptops you may have to press the blue FN switch bottom left the same time as the hold down wireless key

hope this will sort it for you

good luck