Ok everybody. I have had to fix this issue for many people after the 8.1 update.
This is often a driver issue because windows 8.1 will use it's own drivers rather than the manufacturer's drivers for the wireless adapter.
The following steps will fix many people's issues with connecting wirelessly after the 8.1 update.
I'm doing this from memory so forgive any mistakes in the exact dialogue options, but I should be satisfactorily close enough.
Try this:
Step 1:
Go into the device manager.
(If you don't know where to find it, read this or just google it.)
Step 2:
Find your wireless adapter under the category "Network Adapters", (take note of the name on it) then right click on the specific wireless adapter (mine looks like "Qualcomm Atheros AR9285 Wireless Network Adapter") and select "Update Driver Software...".
Step 3:
Windows will ask you if you want to search automatically for the driver, you must NOT choose this option. Instead choose "Let me pick from a list of device drivers on my computer".
Step 4:
Using the name you took note of in step 2, find the correct driver.
(you may have to disable the show compatible, but i don't think i had to. The name from step 2 will be useful here.)
Step 5:
Install that driver and after a reboot (may work without one) your wireless adapter should now work.
Hope this helps some of you.
-Seth
(found some others who have successfully done this here.)
(another method that accomplishes the same goal)