Problem with GeForce Card..

I have a 945mhz processor, 256mb RAM, a Geforce 4 MX4000 64mb video card, windows xp service pack 2…

The problem is when I play some games (like FIFA 2005, Ragnarok Online, Undying), the graphics are all screwed (E.G.: FIFA 2005’s ball while on match is invisible, in Ragnarok Online, i can only see the trunk of the trees of the towns when i get close to them, in Undying which is a FPS i cant see the weapon im carrying, the character’s faces are all screwed and i can only see pieces of them, lot of structures of the places of the game are lost and i can only see its shadows…and lot more graphic problems), I have the latest drivers from nVidia, i have tried changing screen resolution (both in game and on pc) but still all the same, i installed drivers properly like the website recommends and everything…but it wont solve it!
And i also have directx 9.0!

Please help!!