I have a machine that would not pull up any internet pages. It was browsing just fine and then stopped. I am using Internet Explorer 6 and cannot upgrade or downgrade versions as it's a company standard. I am able to ping several addresses from the command line so DNS is working fine. This has happened occasionally on a few machines I support and rebooting them resolves the issues. I'm looking for the root cause as to what could be causing this. Anyone have any ideas on what to check next time this happens to determine the issue?