I would look at upgrading the drivers on the nic cards as indicated. Also hardset speed and duplex on both nic and switch, then add this command to the interface on the switch to see if it helps: conf t, int fa 0/xx, carrier-delay 4, end, wr mem...
For the XL series you will need to set the speed and duplex a little different.enconf tint fa 0/7 (whatever the port number is)speed 100 (or 10)duplex full (or half)endwr memThis should help you with hardsetting of the switch and just do it on the n...
Could be a few differnt issues. I would look at this BugID CSCdr95976 - Windows using Dell console connection reboots switch. And another big issue could possible be with the nimda virus. You can turn off the ip http server and this will help it. ...