WiFi on my Windows 10 laptop has stopped working all of a sudden.what should I do?

Reinstall/update drivers. Search for "update device drivers" in the search. Click on the printer icon one. Then find your wifi card in the one of the drop downs and update/reinstall the drivers. I do not have a computer in front of me and I m on an iPad Air, so if I was unclear, just look it up.

some laptops, there is a key to turn off your radio device. there may be a special key that can be use to turn off it. use it with the function key. mine it's on the F12 button. try pressing the your relevant key with or without the FN key

Take it to your local electronics store.