I don't think that it's been accidentally deleted to some extent since it's those icons are stored in those dll files like shell32.dll, imageres.dll, netcenter.dll etc. Well, the next thing we're going to check now, are some Windows Services related to WiFi and Networking. To open Windows Services Manager(Local), open command prompt and then type services.msc. Once there, check these Windows Services -- DHCP Client, Network Location Awareness, Network List Service, Network Store Interface Service, and lastly Windows Event Log. Set all the aforementioned Windows Services to |Automatic| and set them all to |Start| as well. Or set all of them to |Stop| and then set them all back to |Start| once and for all vice-versa. Once done, log off or restart your lappy. The Windows WiFi icon should display the correct status after that I guess or else. Best of luck XD