Wifi not working on my acer laptop

Hello,
My acer laptop hasent had no wifi for days. I woke up one day and it wouldn't let me go on the internet or anything else. I useualy go to the wifi button in the bottem right hand corner. But it wasn't there. Insted I found a image of a lock the was locked not open. I cant find a way to fix it and I think my laptop is just broken. But was working fine the days befor. If you find a answer please tell me! It would be great! Considering I also use the laptop for school.