I've been having the same problem. I've just installed Windows 8.1 on my sister-in-law's brand new iMac. She needs to be able to get some practical experience on Windows and Office for her future career.
All went well with Bootcamp, installed Windows 8.1 from DVD, then downloaded Office using a keycode, via the Internet. It partially installed, but the wifi connection kept dropping out for no reason. Checked the Networking control panel, tried everything I could think of, but it would work for a time then suddenly drop out.
Back home now and searching the Net (on my reliable iMac!) for answers, and I eventually came across this on You Tube:
Not had a chance to try it yet – back at my sister-in-law's at the weekend and will give it a go then. What this guy Dustin has found is that it is an energy saving setting that needs switching off. The two You Tube videos explain it better than I could, so see for yourself.
There are two possible options you need to look at, one shown in each video. It makes perfect sense because the computer wifi/Internet works perfectly when I'm on the Mac OS, so it's not hardware. Also it's an intermittent fault which is explained by energy saving switching on and off as it chooses.
This has worked for lots of people, but not for others apparently. I'm posting the links in case it helps some of you.
In reply to Bob the Fisherman, I am using Windows 8.1 and it is working fine! I did have to take my computer in to an authorized Apple store. My wi-fi card was bad, so had to be replaced, but they downloaded some files on the Windows side for me and all is working perfectly now! Thank goodness!
I replied to the thread in the wrong order, I'm sorry, this should have gone to the top, but didn't.
Message was edited by: imastitcher