you want to mirror your desktop then.
be warned unless you have a high def tv, your gonna have to use a lower resolution.
my tv which is just a regular old tv, can support 640x480, 800x600, and 1024x768. of course the lower the res the easier text is to read. but for gaming if your tv supports it, you can run 1024x768.
what you need to do is download the nview software from nvidias website.
once installed you can go into the nvidia tab in advanced display properties.
your going to have to chose displays (i think thats it, been a while) from the little menu that pops out on the side. then you have to enable your tv, theres a button next to a p[icture of a tv you press to send video to the tv from your card.
then there's an option somewhere to make your tv a clone of your regular monitor. you need to check that and apply.
with nview you can run your tv in another res seperate from your monitor mind you. so your monitor can be in 1280x1024 while the tv is just 800x600. but for gaming, unless you wan to have to scroll around, you'd be wise just to play games in the highest res supported by your tv.
if that last part sounds confusing, it's cuz it is, but you'll understand what i mean when you see it.