hello all... i have two friends who have a little network going between three computers and a mac, all computers are upgraded with latest drivers and all, but whenever they go into thier My Network Places their Explorer crashes, and on one of the comps the computer locks up... their wondering what could be the problem

some extra info... their using:

ISP = Earthlink
Router = Linkskys
and on the computer that locks up after, its using a = RealTek RTL8139 Family PCI Fast Ethernet Card

anyone know what could be occuring or how to fix it? thanks