Disable the wireless adapter for now and focus on the wired adapter.
If with only the wired adapter enabled and speed and duplex set to 100 half you are still experiencing the constant identifying loop, try going into the properties of your wired card, click the configure button, look for the same physical address property that we discussed earlier and if it set to not present or whatever change the radio button and insert this value
001F16303BCC
which is the actual physical address of your adapter without the hyphens.
OK your way back out of there and reboot.
If you still have the same problem, then I would suggest going back to the router and removing any encryption settings you currently are using and running it open temporarily to see if that helps at all, if so then try adding back the encryption and experiment with different levels WEP, WPA, WPA2 (also you may want to experiment with PSK using AES instead of TKIP.
EDIT: Last paragraph is back to the wireless card again of course. So you will need to re-enable it again.