okay so here's whats going on... my computer isn't working with my tv because when i plug in my HDMI cord into it the sound is coming out of my computer and not the TV. now i know what you are going to say but, the message in the sounds window says it isn't connected when i'm looking, it clearly is plugged in. HELP PLEASE
Assuming it's Windows 7 or newer, try right clicking on the speaker icon in the taskbar and select playback devices. You should 'hopefully' see the device hooked up to the HDMI in the list (mine says HDMI TV). Click on it and select 'Set Default'. It should put a green circle with a check mark in it. Click Ok.
As Popatim said, yes it is a pain. I really wish Windows was smart enough to select the sound device depending on which screen the program is on.