update your graphics card drivers click here
use the seven pin svideo to composite adapter you should have got with the cardd,connect this to your scart lead and connect this to the av1(rgb) socket on your tv.
click start/control panel/display/settings and click the screen 2,set the resolution to 640x480.tick the extend my desktop to this monitor.
play your dvd and drag it from your monitor left or right to the tv screen,it may go black whilst dragging for a moment or two this is normal but should then play ok on the tv.
set up advanced tv settings in control panel/display/settings/advanced/displays/tv here you can adjust colour and contrast sharpness an pal/ntsc output etc.set to pal uk,ntsc(us/jap)may give a b/w picture.
try hydravision (select it from the driver download link above) it will enable more multi desktop features.
black and white pictures are common on nvidia cards when outputing to tv and i am told tvtool works well.i have an ati card myself and never had any problems with using either an ordinary 4 pin svideo lead or the seven pin adapter varity.