Hey All
I have a Qualcomm Atheros AR9002WB-1NG Wireless Network Adapter installed into my Qosmio F750 Laptop. Once upgrading to Windows 8.1 from 8.0 my wireless network adapter no longer worked. I've read all the discussions and nothing helped. The following steps got mine working without having to install new drivers or anything like that.
Follow these steps and you away:
1 - Open up windows explorer
2 - Right click on 'This PC' and click on Properties
3 - Click on 'Device Manager'
4 - Expand network adapters so that you can see the driver name. It had a yellow triangle underneath it for me.
5 - Right click on the driver and select 'update driver software'
6 - Select 'Browse my computer for driver software'
7 - Select 'let me pick from a list of device drivers on my computer'
8 - Mine comes up with two drivers, they are both called the same but one has (Microsoft) at the end the other had (Qualcomm Atheros Communic.......)
9 - Select the one that ends in (Microsoft) and click next.
10 - Crack a beer and enjoy glorious wifi again
This worked for me and hopefully it'll work for you too!