How to use 40" LCD TV as monitor

[CorruptedSanity]

I have a 40" Samsung LCD TV (its HD ready not full HD).

I have connected it to my computer via an HDMI to DVI cable attached to a 8600 GT video card.

I can see a clone of my monitor on the TV but the resolution is just too small. If I sit about 8 feet away, I cannot read anything. 8 feet is normal viewing distance. The size is is proper, meaning aspect ratio is no unbalanced but everything is too small.
If i reduce the resolution, things get better but I dont get the full screen, I have to scroll around the screen.

What am I doing wrong?

Thanks

 

[MagicPants]

Sitting 8 feet away from a 40" screen is about the same as sitting 2 feet away from a 10" screen.

8 feet @ 12 inches/per foot = 96 inches
screen size of 40 inches / 96 inches = 0.4167 size/distance

24 feet x 0.4167 size/distance = 10 inches

I think if you sat about 4 feet away from the TV you would get what you expect.