Sudden limited connectivity problem

Hi,
I was wondering if anyone could help me with this problem i just got.
I have 3 computers ( 2 laptops and one desktop) connected to my DSL conection through a linksys router(not wireless)

This connection has been running fine for the past 2 years. Yesterday all of a sudden when one of the laptops was turned on the other two computers suddenly went on limited connectivity from working fine.

nothing was installed on the laptop that was turned on last but i do have windows automatic updates on.

I can connect to the internet directly with each of the computers its just when i connect them through the router i cant

Does anyone know how this problem can be fixed

Thanx!