HD TV but is it HD?

[jimmyob]

Just got my X360 home and put it on the TV we have. It's apparently HD ready but in the manual says the only socket that HD officially works on is the DVI socket. So i connected my VGA cable to it but it doesn't recognise the input.
I've been using it as the TV's "PC" input, it looks ok but how do i know it's actually in HD?
Is there anyway i can test for HD?

 

[jimmyob]

in PC mode i'm running it at 1370x768 or something like that.
the DVI port is supposed to be an HD port so i'm assuming that's ok.
It's just i dont understand why the TV wont pick up the signal as HD from the xbox.

 

[jimmyob]

If i turn the HDTV switch ON on the cable, the screen goes blue. so i'm assuming it only works when the DVI cable's in...