Com0com Download
Null Modem Emulator Com0com
For anyone having the driver signing issue on Windows 8, the bcdedit answer above doesn't seem to work because Windows 8 has some sort of new Secure Boot policy that prevents running that command successfully, even as admin (on my machine, at least). What worked for me was running shutdown /r /o /t 00 as admin, then selecting Troubleshoot, then Advanced options, then Startup Settings. Click the Restart button to restart and enter the Startup Settings menu, then select option #7 ( Disable driver signature enforcement).
The com0com download will contain a setup.exe to install the program. Install the program, ensuring you are allowing the signed drivers to be installed. The com2tcp program contains a stand-alone executable. Place this in a convienent spot for runnning it.