I've been monitoring the DNS server breakdowns fo a week. The problem is intermittent over periods of usually about two hours. Prime times are between 4.30pm and 7pm...then 12.30 and 4.00 pm.I'm getting nowhere in repeated attempts for solutions online...my provider (Telstra) says it's a line fault...my checks indicate no line faults. My expert helper can't identify a specific cause ( set-up has been checked). Is the whole system overloaded and about to get worse? Who can I ask now? Thanks for suggestions Tassiebill

Not sure of the relevance to Windows 7 in your post. However, you seem to think that you have DNS problems. Why not try another DNS provider? Google DNS & OpenDNS spring to mind. Please note that the above line was not suggesting that you use Google search for DNS as Google do indeed provide their own DNS servers :)