Nvedia driver

Hello, i have a emachine el 1200. windows xp-32 bit. my video card is NVEDIA GEFORCE 6150SE NFORCE 430. i can keep my color in at 32-let alone at 16. i have checked and rechecked all other major drivers, and everything is updated, and there is no other conflict, except this problem. i have gotten hold of them a couple of months ago, and they had me run diskkeeper, and reinstalled their driver. it worked for about two weeks. it is getting really frustrating! can i up date this driver higher than 430-without doing any damage? or do i need to change eveything?? this machine is only 2 years old. thanks doreena