The Page cannot be displayed-error message

hi..i've had this pc for a few days..over the last couple of days,when i've brought up random sites,at the top of the page ,there's a double banner of the error message "The page cannot be displayed"..however,the page does display beneath the message,albeit in a cut down form,size-wise.the scroll bar then cuts down to match the size of the shortened page. wondering why the error message banner keeps appearing when the page does,in fact,display.thanks!