Hi for those who are having trouble installing nvidia, " DO NOT MESS WITH THE KERNEL OR MODIFY ANYTHING"!
This is the correct way to go:

1) download synaptic : apt-get install synaptic.
2) make sure Software sources is available under ADMINISTRATION.

DO NOT ACTIVATE ANY UPDATE FROM SOFTWARE SOURCES.

3) Here is the best solution for you ( tested and running on HP G70, Gforce 9200M , Backtrack 5 Gnome 32bit).

Open terminal and paste: add-apt-repository ppa:ubuntu-x-swat/x-updates
*** The system will ask you to if you want to install " add " say Y.
Make sure the ppa is installed, re-paste the above command if necessary.

Again in the terminal : apt-get update && apt-get install nvidia-current nvidia-current-modaliases nvidia-settings

*** Reboot

Again in the terminal paste : nvidia-xconfig

*** Reboot again and you're good to go.

Hope this helps.
GD

Ps: you might want to fix the grub, do it this way; nano /etc/default/grub
Scroll down to : #GRUB_GFXMODE=640×480
Uncomment # ( take # off the script. like this : GRUB_GFXMODE=640×480)
Set you screen resolution according to your screen, mine is 1440x900 !
Now hit : CTRL+o to overwrite >>Enter, CTRL + x to save and exit.
Now in terminal : update-grub

Good luck.
GD