Yep.
When investigating network issues, you need to use the OSI Model and begin with layer #1 (the physical layer) the physical connection.
I don't want the OP assuming that the problem might be with Windows
When it is as likely or perhaps even more likely something physical and those line connectors is where I would start. Either placing another computer in exactly the same location or by using my 100 foot cat5 cable to take them out of the diagnostic process. I keep one in my troubleshooting bag so when I go into an environment I don't have to rely on any customer wiring, I can bypass all their existing wall jacks, cables, multiple switches, etc., and just go straight from the computer to the switch ports on the router.