MY WIFI Adapter seems to be disappeared

help please, 

recently i dropped my dell xps l702x
it was fine nothing but a scratch
it was all good for like a month or more
till i had this problem with my wifi
at the  beginning the connection to internet went off and reconnect again 
then the second time my wifi went off and i mean the light went off and connection lost

i restarted my windows and it was back again
third time i just moved my lap top and place it in another place
wifi went off and i tried to get it back with no luck
it was like that for several days with several rebooting and no luck
I checked for the driver it wasnt found in device manager 
there was just the cable lan no > intel wifi adapter as its not present in the laptop 
i lastly installed windows again  and no luck
this very moment i could access wifi out of no where
i did nothing just restarted windows  and it came back
am afraid i will restart it again and will loose it
I wounder is it a hardware issue or is it a software ?
and what is the best way to make sure and to solve it
 P.s  i did re-installed driver it says it is installed successfully but still no wifi adapter in device manager or any trace for it
 i tried the Fn + wifi on off  no control no effect
F1 F1 F1 F1
 please any idea !!

thanks