One of our computers has started to constantly acquire a new lease from our DHCP server (a Trendnet router.) I get these 3 messages every couple of minutes, and the messages are logged at the same time:
Your computer was successfully assigned an address from the network, and it can now connect to other computers. The system detected that network adapter Local Area Connection 3 was connected to the network, and has initiated normal operation. The system detected that network adapter Local Area Connection 3 was connected to the network, and has initiated normal operation.
(Yes, the last message is repeated twice.)
Because of this, the computer is having constant problems with communicating with other computers on the network. It's used as a CruiseControl .net server, so it intermittently fails to copy files to network locations, and it fails to connect to our subversion server.
The lease expiration time on the router is 1 week, so I don't think it's an early expiration issue and I'm not having this problem with any other computers on the LAN. I've updated the drivers for the network interface and that didn't seem to have any effect. I've power cycled the router, and I've rebooted the computer. I installed a PCI network card and it's still having the same problems, though the time between the message sets is longer (about 1/2 hour instead of a couple of minutes.) The last thing to be updated at the time this problem started was a Windows Defender definition, so I don't think it's any recently installed software.
My question is: are there other things I can do to debug this problem, or does anyone have any idea what is going on?
EDIT: I've also changed ethernet cables and ports on the switch and I still get the same problem.
EDIT: I tried reinstalling and restarting TCP/IP (http://www.mydigitallife.info/2007/06/19/reinstall-and-reset-tcpip-internet-protocol-in-windows-vista-2003-and-xp/), but that didn't seem to help.