After nvidia module build, black screen & no access
 

My XF86Free was working fine with the nv driver (before I got and installed nvidia-kernel-commun & related). I tried to actually install the nvidia driver & I built it. The build went fine and it lseemed like it will work. After a reboot, the screen goes black (no signal from the monitor) so I can't even get in to replace XF86Config-4 with the backup I made of that file prior to the build.

How can I somehow get in and replace the file for now?
I'll deal with the building etc later on I guess.

The screen goes black immediately so you don't even see bootup messages? Strange. You didn't by chance fiddle with the frame buffering in grub? Anyway, you can use a linux livecd to edit files. Kanotix, Knoppix, Damnsmalllinux come to mind.

EDIT: Come to think of it, don't you have another kernel you can boot into? IMO you should always have two kernels installed if you bork one up.

Thanks for the suggestion. I did get in finally.

For future reference, any time the X server fails to start, you can switch to one of the consoles to administer the system. Press Ctl+Alt+F1 (or +F2, F3, etc.) to switch, and then login.

Thanks a lot, I'll keep it in mind.

You should try it right now to see how it works. It's simple and very useful, especially with X issues.

Oh, and you need to know that X server usually runs on console 7, so press Ctl+Alt+F7 to get back to X. You'd be pretty mad at me if I didn't mention that. ;)

Mmh, and here I thought you couldn't login at all. Oh well.

I did try and it works great. However, when I was trying to boot I had a totally black screen.
The way I finally got in was by trying the other kernel that was listed there,
I had a hunch maybe it wouldn't use X, that was the case.
I am glad you mention these, as I will experiment later on to make the nvidia driver work with the card
so this should work if I do not reboot after I edit the conf file but kill X and start it again (I hope).
Thanks again

Sorry, if I wasn't more explicit, that was the case. I just didn't feel like cluttering too much if you will.
I did try the Knoppix boot, but it refused to save the changes to the file (read-only file system, even when I chose the other root console from the K menu (I read somewhere you should use that root console)).
Is there any way to save changes on a file on your hard disk from a Knoppix boot? (that could be handy in the future) The other kernel listed happened to not be configured for X. I got in and edited the file.
I guess you learn by spending some sleepless hours at the console...but it sure helps when you get feedback.
Thanks for your help

If the partition is mounted read only you can do "sudo mount -o remount,rw /dev/hd?? /mnt/hd??"

I am glad there is such a simple and elegant solution. Thanks again

Just a little side note. A kernel is never configured for X, but rather the system is. When you install Debian, it makes at least two entries in the GRUB bootloader: one using the normal kernel that you configured, and which will run all the systems as normal; and a second, rescue/troubleshooting version, which if I understand right has a lot of modules removed and (I think) boots the system into a lower run level. You probably just selected this second kernel configuration.

For a little detail on runlevels, see here:
http://openskills.info/infobox.php?ID=1104

You'll see, for example, that runlevel 5 is "multi user with graphical environment."

Amen. Remember that once you are an expert hacker. ;)

Got it, Thanks.
That will take some time I suppose... ;)