your NIC may very well be enabled to *listen* for DHCP, if your router isn't enabled to *send* it, that won't be to some big avail
Your router must be accessable using a HTTP protocol, or at worst, a Telnet protocol. So what you can do is, set up your puter's IP address manually (it's temporary), like, 192.168.2.2 / 255.255.255.0, then fire up your browser and try
http://192.168.2.1
if IE spouts an error click start->run, and type "telnet 192.168.2.1"
That should at least give you some sort of command line.