Wifi is not working

[aaab]

 Recently I opened my phone to find the Wi-Fi icon in the upper right missing. I tried to turn the Wi-Fi on, but the process just hung there. I rebooted and got the same thing. I checked under Advanced Wi-Fi and found the MAC address unavailable.

I rebooted several times over the next few days, and finally the Wi-Fi was back to normal. That lasted for three weeks, and then, boom, back to the same thing for 3 days, then Wi-Fi was on for three days and then today, back to no Wi-Fi and MAC address unavailable.

Any ideas on how to remedy this situation, short of a factory reset? I've heard that it could be an android system file that needs to be replaced by downloading it, although I know not which file. Could a recently installed App be causing this? My guess is that it's something in the boot process. Please help!

[Samuel1]

I suggest that you try to repair the phone software using PC Companion..

Before repairing your device you may want to backup your information first. Check out this topic for more information on how to.
How to backup?

If the issue should still remain I think that this needs to be examined and fixed at a repair center. For more information about how to submit your phone for repair and where, contact your local support team.