What is the problem with the adapter on booting - a failure to get an IP address from the router?
If so, go to "Start > Run", type SERVICES.MSC and click OK. In the Services window scroll down to the DHCP Client entry, double click it to open its Properties and check that it is "Started" and that its Startup Type is set to "Automatic".
If that's all OK, try giving the network adapter a fixed IP address in the same Subnet (IP address range) as the router. Post back if you need instructions for doing that.