We have a couple of Mac laptops on a wireless router and one Mac desktop running on ethernet much of the time and have never had an issue with losing the wireless signal. When my son is home from college, he brings his PC laptop running Windows XP to use at home. He connects to the router using an ethernet switch. Whenever he is online, the wireless signal randomly drops out. His wireless function is not active when he is on ethernet. Any ideas or solutions would be greatly appreciated.