I had a similar problem and found the fix. The issue: Windows Vista
machine connected to Linksys 8-port gigabit switch. The switch is
connected to a router (of course). All other non-Vista machines
connected to the switch worked fine. But, the Vista machine displayed
"network cable unplugged" message when connected to the
switch...however, it worked great when plugged directly into the router
(same cable used when connected to router and switch so I KNEW it was
NOT the cable). There were many suggested "fixes" out there, but the
ONE that worked was... Control Panel / System / Device Manager / Network
Adapters / Right Click on your network adapter / Properties / Advanced
Tab / Speed-Duplex Settings----CHANGE THIS SETTING TO "100 Mb Full
Duplex". The "Auto" setting apparently does not work when the machine
is connected to a switch. I don't completely understand why this
worked...but it did work!
Barry


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BaRut