I too am having the same issue on 8.1 the virtual adapters will not enable throwing an error that they cannot bind to a physical adapter this is the Event Log pertinent info.
Log Name: System
Source: iANSMiniport
Date: 7/10/2013 1:23:42 AM
Event ID: 4
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: Pronto
Description:
Unable to bind to physical adapter. To resolve, remove the adapter team and then create a new team.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="iANSMiniport" />
<EventID Qualifiers="49159">4</EventID>
<Level>2</Level>
<Task>0</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2013-07-10T08:23:42.294168800Z" />
<EventRecordID>1160</EventRecordID>
<Channel>System</Channel>
<Computer>Pronto</Computer>
<Security />
</System>
<EventData>
<Data>
</Data>
<Binary>000000000100300000000000040007C0000000000000000000000000000000000000000000000000</Binary>
</EventData>
</Event>