Just when I thought everything was running smoothly on my new HP......

I'm having a problem connecting to a couple of my regular internet sites............I've had the same opening page on my internet for years......it has been loading just fine until this morning. Now, I'm getting an "unable to display" page instead. This is also happening with the mediadomain.com site that I like to look at regarding the couple of soaps that I watch. I've tried the diagnose problem efforts by Explorer, but it doesn't detect any problem.....I've also tried to connect to the sites through Bing and I still get the same unable to display message......what's up?? Anyone have any ideas??