HYPER-V Manager Network Connection/adapter issue

Today, I have downloaded windows 8 and started configuring a new Virtual machine on Hyper-v manager.Unluckily,while configuring Network,the drop down yielded nothing (just showing ‘Not Connected’). Microsoft Synthetic Ethernet Port (Instance ID {EAC7FE2C-1A20-4F2B-A0C0-E328A5AE5F56}): Failed to Power on with Error ‘The system cannot find the path specified.’ The switch port connection for “Network Adapter” is invalid. […]