[blata]

first what environment are you typing init 3 in? That is have you switched to a vertual ternminal or are you doing in from within a Xterm window?

hold the LEFT ctrl and alt keys then hit one of the F key between 1 and 6 (there are six "vertual terminals living on the f keys. Your X display acctualy lives on F7.

once loged in as root on a vertual terminal type

whereis init

you should get somthign like this.
whereis init
init: /usr/src/linux-2.4/init /usr/src/linux-2.4.20-28.9/init /sbin/init /etc/init.d /usr/share/man/man8/init.8.gz

/sbin/init is teh one your looking for. The sbin directorys hold exacutables that only root can access.

if its there then simply type init 3 enter you should see some services shutting down. and to check that X is realy dead hit ctl+alt F7 and it will be a black screen with a blinking curser.

go back to your vertual turminal and run your NVIDIA*.run. Hopfully all will be good.

when your XF86config is eddited type in init 5 to go back to graphical mode. Be sure to go back to your virtual turminal and log out of root.