"Uninstalled Communications fixed problem! Why?"

I solved my home networking problem but don’t know why! I recently began cable internet service and the tech could not get one of my computers to accept the signal either via the Ethernet card or USB. He had no problem with my other computer. Later on, I went back to the 1st computer, replaced the Ethernet card with a new one, added the software, went thru the internet setup wizard, but could still not get a connection. Finally, I went to Windows Setup and unchecked the Communications option and removed everything there thinking to reinstall and possibly fix any corrupt files. To my surprise I got my internet connection without reinstalling anything. It now works fine, but what happened?