Windows 2000

I have wondered for a long time why two computers running windows 2000 pro that are connected to the by a netgear hub model ds-108 are getting kick off the internet. There is also a 2000 server machine in this buiding but is not being used. We wouldbe online then suddenly internet explorer hangs looking for the page. I have look everywhere and have not found a solution. Please point me the right direction.