I was messing around with the wifi issues today and I think I found another link - bluetooth.

I have a bluetooth mouse that I usually use. When the mouse is disconnected and off, like now, the wifi on the Yoga 2 works fine. If I connect the mouse or my bluetooth headset, the wifi does not work.

All,

Please see this MS article that just came out and may be the fix.  I'm going to mark this as the solution to guide customers to this post, but we will continue to follow this thread.

https://support.microsoft.com/en-us/kb/3084164

I had the same problem, ended up being Kaspersky Internet Security. As soon as removed this WiFi networks became available. 

After countless hours of troubleshooting, uninstalling my antivirus BitDefender Total Security 2015 fixed the issue. This is unacceptable on either Lenovo or Microsoft's end, considering Bitdefender 2015 is supposedly tested for Windows 10. (Which leads me to believe this is Lenovo's issue, also given the terrible reputation of WLAN  on this laptop)

I had the same problem.

Booted into Bios and turned wifi  off an on  (it was on initially).

Then I saved the settings and after the reboot: Wifi worked properly!

Weird problem. 

No my Yoga performs well!

Greeting from the Netherlands.

i had same issue and have a quickfire resolution that worked for me on a brandnew yoga. 

it looks like windows 10 cant pick up the network adaptor driver during first restart after install because a hard restart is needed to kick it into life  however i found it doesnt need a full stop start. 

with laptop still on 

press the power button once (dont hold it down) to put it into sleep mode (flashing light)

once asleep leave it 15 second then press the power button again to wake it up

hey presto - it detects the network adaptor as it starts up the wifi link . (athough it had forgotten my wifi login details)

I hope this works for you.

Senderos

Hard reset (holding down shift while clicking on start -> power -> shutdown) worked for me. I had no VPNs installed.