I have my Windows Vista laptop connected directly to the router via an ethernet cable, and every time I switch the computer on, the computer cannot connect to the internet. It comes up as limited or no connectivity, I am assuming because it has not been assigned an IP address by the router - not too sure if this is right.

The problem is usually fixed either by performing a repair through the networking control panel or removing and re-inserting the ethernet cable. It will also connect without doing any of these if the computer is left idle for about 20 minutes.

It will connect fine wirelessly without the need for any of this, however I would prefer to connect via the cable. Any ideas how I can fix this? I have replaced the ethernet cable and router already (identical model) but these haven't helped.

Thanks for any help on this.