My IE 5.5 would hang when a link didnt load, it'd hang the whole system. Then I noticed it was really any network job that was waiting for a response would hang the whole pc. It would only hang for a few seconds, but it was very annoying.
I knew w2k didnt identify my old linksys nic properly, and was using a generic driver, so I got a new nic and swapped them out and it's fine now. Maybe not the problem as you have, but it maybe worth checking it out.