If you are a user of Wireshark Windows 8 might be a bit disappointing for you since WinPCap is not supported on Windows 8. While it might seem a bit hard to believe you can install WinPCap on Windows 8 and it works pretty fine except for Dial-up and VPN which will not work.
To install WinPCap use compatibility mode and set compatibility for Windows 7 as shown below.
Next open Wireshark and click on Interfaces. Select the interface which has packets incoming and outgoing in case you are unable to identify the interface you want to work upon.
This way you can use Wireshark or other network analyzers which depend on WinPCap. The problem is due to some unimplemented features in Windows 8. Although as the final version of Windows 8 comes up this might be resolved.