I'm having trouble with hardware-accelerated display with an ATI Radeon 9200SE. When I first installed Debian it worked fine with fairly good 3d accelleration (although I dont know what driver was providing this). I then decided I wanted to run a dual-head display so I installed ATI's proprietary Linux drivers and now X is stuffed. When it tries to load the screen turns off and I cant even Ctrl+Alt+F1 to get a console. How can I get back the 3d drivers that come with debian - I tried reinstalling X but it appeared to have no effect.

Make sure that the computer does not boot into XWindows automatically... if necessary, remove "gdm" or "kdm", or remove symbolic links pointing to them in runlevel dirs in /etc/rcX.d. You can check the default runlevel from /etc/inittab.

Then edit the XF86Config-4 (or xorg.conf) in /etc/X11 and remove all fglrx stuff. You should use driver "radeon", not "fglrx". It might be best to create or restore a previous XF86Config-4. Editing a config created by the ATI installer is probably not the easiest way out.

Also, if you did not already do it, remove all ATI kernel modules. The installer should have a commandline switch to do an uninstall.

If the system is unusable, use Knoppix or similar LiveCD to boot and edit your configs from there.

start up in recovery mode runlevel=2