I tried many ways to solve this problems, non of them works. Until I found this solution.
Two steps required. Before moving on, please make sure your system is Windows 7.
Download and install the newest driver for your wifi from here (32 bit, 64 bit) (Very important).
Click start, enter “cmd”, press “ctrl + shift + enter”. This allows you to open DOS under admin.
Copy paste following two commands into cmd, one by one.
Now launch your virtual router, it should work well.