I have decided to join this discussion as it was my first port of call when I experienced this issue which started last weekend after upgrading to Windows 8.1. My network adapter is a Netgear N300 (WNA3100).
I tried every single option on the net practically plus advice from someone on the Microsoft forums but whilst a lot of ideas worked to start with within a couple of hours maximum the issue would return.
The only thing that reconnected would be to unplug the adapter from itself then reconnect but this of course isn't a fix rather than an annoying reset.
Then I came across this site http://pureinfotech.com/2013/09/16/how-to-fix-wireless-limited-connectivity-windows-81/
I tried the first options but again only a temporary fix. However I then tried the bottom option which is :
Update: If after trying all of the above solutions, you still having Limited Connectivity problems, changing the following network settings could also help.
Note: Apparently the following changes works best for Surface RT devices. However, you can try this solution on any Windows 8.1 PC, including Surface Pro.
1 Open the Command Prompt as administrator (refer to previous steps).
2 Next, type the following commands (one at a time) press Enter and OK on each one:
netsh int tcp set heuristics disabled
netsh int tcp set global autotuninglevel=disabled
netsh int tcp set global rss=enabled
Then use the following command to verify all the previous settings are disabled:
netsh int tcp show global
3 Restart your device and see try to connect to your network.
It's now been around 15 hours and the connection hasn't been disconnected or become limited once and I have tried rebooting a couple of times and waking the PC from a sleep and all seems well.
Therefore I thought I would post this as it may help others with the same issue.
One thing is though I have absolutely no idea though what I have actually performed here but thought it was time to throw caution to the wind so if anyone has time to explain what the steps may have done I would appreciate it.
Just an update with regard to what I performed above.
It's been a few days now and I haven't had any "limited" connection.
What I have had a couple of times is "no connection" due to "no networks being found" but all I do is click on the bars in bottom right corner and connect to my router and all is well again. Still a little annoying but certainly better than having to disconnect and reconnect my adapter every half an hour!! So hopefully the above steps worked ok for me although waiting like everyone for a permanent fix from MS.
The only issue I did have really afterwards was a PC freeze during maintenance where only the mouse pointer actually moved and only cure was a hard reset turning off the power. Fortunately I ran a scan and the problem hasn't arisen in a couple of days. Another Windows 8.1 issue by all accounts.
A shoddy update Windows 8.1 it certainly is and shoddy performance by MS by failing to admit issues and finding fixes for them. I mean if your car stopped working after a full service would you be expected to trawl the net to find fixes for what the garage ruined?! I don't think so!!!