The problem arrises when it's a 100mbps only NIC, although those are quite rare.

Or when you have a 10/100 nic that's been forced into 100-only mode by the default driver installation in Windows NT 4.

Had that happen to me once, couldn't figure out why the NIC wouldn't connect on our network and literally set the machine aside in favor of another computer. It's still sitting there, even though I discovered the problem on an identical machine a few weeks later.

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Tony Fabris