The title of this could also be "How to install WinPcap on Windows 8" or "How to install NetScanTools Pro on Windows 8". WinPcap is the packet capture driver used in both Wireshark and NetScanTools Pro (and LE). If you try to run the Wireshark installer, everything appears to install OK until you get to the WinPcap installer that it launches separately. The WinPcap installer refuses to run and shows an error about an unsupported operating system.
The solution is to run your installer in compability mode. Here's how:
1. from within Windows 8 (32 or 64 bit) get to the desktop and launch Windows Explorer.
2. locate your installer file, example: wireshark-win32-1.6.2.exe and right click on it to bring up the menu.
3. select "Troubleshoot compatibility" and wait a few seconds for it to do it's thing. Then click on "Try recommended settings". It will most likely show Windows Compatibility Mode of Windows XP (service pack 3).
4. Click on "Test the program..." the installer will start - follow the installer directions as you normally would. When you get to actually running the WinPcap installer you may see a message "This program has compatibility issues" - select "Run the program without getting help". WinPcap should now install.
5. When it's all done, click on Cancel instead of Next back on the Program Compatibility Troubleshooter window.
The problem is not Wireshark or NetScanTools Pro. Those installers both launch the WinPcap installer. It is the WinPcap installer that needs to be updated.
The good part about this is that now Wireshark now properly captures packets and NetScanTools Pro can both send and receive packets using WinPcap.
Update Oct 10, 2012: winpcap.org still shows version 4.1.2. With the public release of Windows 8 only a couple weeks away, we still are waiting on an updated WinPcap installer.