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Error Government Website
Error displaying government website for example pictures are not displaying then you have the wrong value set for mtu in your modem or router.
Many of the pages are JSP pages so a setting in the router needs to match those supplied by your broadband supplier
I changed mine MTU value from 1492 to 1458 (my provider is Zen)
Now the websites work correctly
List of sites
HM Revenue and Customs
Forms failing to download
Pictures failing to display
When using tools --> Windows Update I was getting "Page not found"