We have four computers connecting via our Netgear router. Two are connected
via cable and two laptops via wireless.

Now one of the will connect to the home network (in that I can access the
shared files on the other pcs etc) but won’t connect to the internet. I’ve
checked and triple checked the settings and they seem fine. I gave up and
set up a new wireless network and the other laptop connected without any
problems at all but again this one just won’t.

I changed the IP to a static IP address with no success, I’ve turned off the
firewall.

Any ideas?