A quick Google search for "res://ieframe.dll/dnserror.htm", brings me to this page as the second result::
2eb96418-e944-4ee9-a4f3-ff28980c36a2/
Seams this is a somewhat common issue with IE 7 that is either caused by a security patch, or installation problems.
There are a number of suggested fixes in that thread, hopefully one of them will help you out.