Elton, thanks for the answer. I think the virtual Wi-Fi adapter only appears in the Device Manager in Windows 7. Enabling it certainly makes sense.
In Windows 8 the “Microsoft Hosted Network Virtual Adapter” is created after netsh wlan start hostednetwork. The virtual adapter appears then in the Network and Sharing Center.
If this fails, disabling the Wi-Fi adapter in the Network and Sharing Center and then enabling it again might help. Actually, I have to do this quite often in Windows 8, especially with some network routers. Sometimes only rebooting helps.
Another thing I have found is this KB article. It appears if Power Management is disabled for the wireless network adapter then this can cause the virtual Wi-Fi adapter fail to start. You can enable Power Management in the Network Sharing Center > “Change adapter settings” > Right click the Wi-Fi adapter and select “Properties” > “Configure” > “Power Management” > Enable “Allow the computer to turn off this device to save power.”
I wasn’t able to reproduce this problem under Windows 8. So maybe this is only a Windows 7 and Windows Server 2008 R2 issue.