First check your
/etc/X11/xorg.conf file. In the device section it should list the driver as "nvidia".
To disable nouveau try adding
blacklist nouveau to the
/etc/modprobe.d/blacklist.conf file. You chould be able to do this from recovery mode assuming that Backtrack 5 has a recovery mode like Ubuntu does. Then reboot and see if you can get to the desktop.
If blacklisting nouveau alone does not help, try also adding these to
/etc/X11/xorg.conf, each on a separate line:
Code:
blacklist vga16fb
blacklist nouveau
blacklist rivafb
blacklist nvidiafb
blacklist rivatv
See this for reference:
http://www.ubuntugeek.com/howto-inst...ucid-lynx.html