look pal, it sm times depends on the type of configuration u hv on yer pc.
Directx 9.0 may be installed, bu' u have to have at least a 128MB graphics card/acceleration in ur pc.
u say it runs for sm time, then auto turns off, eh? well ur pc also shud have at least 512 MB of RAM in it.
an yes, nfs mw supports only sm graphic cards.
my best one for u is try on an Nvidea GE Force 7000 or 8000 series.
will do a lot and it is also cheap these days. so go build up ur pc an dont stop gamin'!!