Need help setting up dual monitors

[McRackin]

I have a 42" 1080p TV that I'm trying to connect to my PC with a dual monitor config so that I can watch movies on my TV. All of my HDMI inputs are being used so I bought a DVI to Component cable. I connected the DVI to my PC (560ti vcard) and the component to the TV, went into my monitor setting on my PC and setup so that both displays show the same picture. I keep getting "no signal" from my TV after applying settings. My PC recognizes my TV is present but still no picture.

I've never done this before so can someone help me?

Thanks