I can't tell from what you wrote if you have addressed your display settings. http://support.microsoft.com/kb/976064

shows how to do it along with screen shots . You can get to display settings several ways. I tend to just right click on empty area of desktop and select properties and then settings. Your monitoring devices do need to be on in order for the computer to find them. You can set up the resolution for each and designate which is primary. If you tend to switch back and forth between single and dual monitors then you may need to reset this more often.

I am also unclear if you have addressed changing the input on your tv, if not then simply set the source for input.

It might be helpful to others attempting to help you if you say what you are using for each monitor and then referencing it that way. At least for my brain using the words "this" and "the other" tends to get confusing in very long sentences. Others may also find that they need to know your operating system to give you specific instructions.

Good luck and sure you will enjoy this once it is up and working.