I'm having the same question. However, my networks have been pushed via GPO so I am unable to "forget" them. I have removed the wifi card, reset IP stack, even removed the networks by deleting the directory in C:\Windows\wlansvc\Policies
Other WiFi networks connect just fine, just this one.
I get it to work sometimes, but a few days later it goes again.
Checked 802.x certificates etc, but cannot figure out the problem.