killed my sound

I tried using the world webcam last night, it just kept trying to load, so I gave up and decided to watch a recorded show.  All was fine until about half way through the show when something popped up in the bottom right corner, then my show froze up.  It would start for a moment then freeze, it also killed the sound which I could not get back on even when using my tv remote.  This morning I reset the HD box and it's back to normal at least with the sound, I haven't checked yet for the recorded show.