Router keeps resetting when connecting 2 computers

When I connect two computers, wired, two my Netgear router, the router keeps resetting every 10 seconds. I have tried DHCP setting and static IP, but that dows not make any difference. One desktop and one laptop both running XP Professional. Connecting only the desktop or only the laptop does not result in any reset. Also tried installing another NIC in the desktop. No solution.

Can anybody help?