Cars - NASCAR 2003 Sim help needed-VERY ODD PROBLEM

OK-I have a XPPro, 1 gig ram, Nvidea 128 card,plenty of free space,
etc.....
The game and all the add ons ran just fine, for a long time.
Then suddenly one day, it crashed the computer into restting.
It never ran again, everytime it would crash to reset the computer.
I uninstalled it all.
Reloaded the basic Nascar 2K3 game, stock from the CD Rom, and it STILL
crashed to reset.
I even tried adding the NO CD thing to it, crashed to reset.
WTF??????????

I even went so far as to install the basic game on my F: drive-where
only Flight Sim 2004 is located--same thing crashed the computer into a
full restart.

So what is wrong, and how do I fix it?
I am assuming its a registry problem?

I have several other games far more graphic intensive than N2K3.
BTW Nascar 2002 runs just fin, with a ton of addons--

ANYONE WHO CAN OFFER ADVICE????

H E L P ! ! ! ! !