Hi I had a similar issue and I'll tell you how I fixed it.
I was on steam and tried downloading a patch for a game. It wouldn't connect to the steam server. My wifi was working fine at this point. I decided to restart the computer, and see if that made a difference. If did... I couldn't see any networks on my wifi when it came back on. There were no windows updates or anything like that.
This issue keep on happening the next day. I looked at downloading the Live Update 6 from the msi website. That didn't work in windows 8.1. I didn't try that hard to get that working to be honest. I just moved on..
I then went into "system" then "Devices" then disabled the wifi device and re-enabled it and it started to work again. I assume the power switched off, and it never got the message to turn on again.
Hope that is all it is.