Hello, I have my PC's linked together too. Along with following DIGI's advice about not using network cards in ProTools systems, I bought what is called a USB Network Cable. Basically, with the installation of some application specific software, my two computers are linked together via 1 15-foot USB cable from the USB ports. No cards in either CPU. This system is fast, reliable, and is in accordance to DIGI's specs. I simply load the PC-LYNC software into the Windows Startup, and when the computer is turned on, they are already linked and ready to go. Talk about cheap too. I think this setup cost me $25.