problem detecting Wi-Fi

Hello!! I have a big problem, my computer doesn't detect anything that has to be with wifi. Actualy, it says it doesnt have installed wifi.  I can only use internet if I conect the cable of Ethernet.  My computer has been having this problem for almost 6 months.   I've tried solving with internet conections solution, with internet adaptators (but in this case doesn't apear wi-fi options). I have restarted the computer many times.  What can i do to solve this problem?

I appreciate very much your help. Thank you.