Here's what I have and being the complete newb I am, I have no idea how to get these to work together. Samsung LE46C530 is my TV, Sony STRDH820 is my receiver, LG LHS-55TBS are my speakers. The way I have it currently setup which isn't working is I have my PC plugged into my TV via HDMI and then an optical lead going from TV to receiver. I know almost nothing about this sort of thing so I'm up against it here. Also, I know technically I could plug my PC into the receiver via HDMI and then have HDMI going out to the TV but when I tried this I noticed quite a bit of video quality difference.
I really don't know what to do, any help would be hugely appreciated.
Links to TV and Receiver specs if that will help: