Hi, this morning when I was turning on my computer, it stopped at grub. All it wrote was: GRUB with white leters on the black screen. No commands worked, only shutting it down.

I've found out with the help of a rescue cd, that on my main drive (hdb) I have to partitions, a boot one and a main one. Both has got a /boot dir, but the one on the small partition has only got fc3 files (the other one has got the fc4 stuff).
I don't know if this is the reason, as I think it has been like this since I installed fc4.

I also tried to "upgrade" the system with the install cds, to reinstall grub, but it said that: "No kernel images was written, nothing has changed".

Has anyone any idéas?
Or is there some way to get debugging/log info for grub, to see what it's problem is?

to have 2 /boot partitions means one was FC3 and one was for fc4.

check out your partitions again with (knoppix?) cd and see what your second partition's /etc/fstab file says its likely you are now to use the second /boot.
then check out what your /boot/menu.lst files says and print it out
then while in knoppix re-link your booting files to the mbr by opening a terminal and then issue commands
su
grub
root (hd0,1)
setup (hd0)
quit

where I am assuming the root command is to link to your second partition.

or check out my trouble shooter link and just use commands

/boot is not mentioned in fstab, and the is a menu.lst both on the boot partition and in the boot folder, both linking to the grub.conf in their directory.

I asume The boot partition is just from fc3, and then when I installed fc4 I forgot to say, that it should use it.

I booted from the fc4 cd1 in rescuemode, and tried root(hd1,2) setup(hd1), but nothing happended.
(My main disk is number 2, number 1 and 3 is just for media. Actualy number 1 hasn't got any partitions, no fdisk, I just mount it as "mount /dev/hda /.../media/")

in your first post you said your main drive is hdb = ide cable 1 jumper as slave

whats the master link? a optical drive or a another hard drive?
how many drives do you have and what are their jumpers please, are any SATA?

does your bios boot to ide b4 sata if you have sata as its makes a difference to where we put the bootloader.

I don't understand your use of main disk number 2 stuff, can you be more explicit?

(2) even if you have 2 drives please read how grub numbers partitions
root (hd1,2) tries to go to the third partition on the second bios detected drive

3) I suspect your fc4 has /boot under / as per my howto and therefore you ignore the first partition.
therefore, if you now understand the numbering system

su
grub
root (hd1,1)
setup (hd0)
quit

and reboot assumes you have 2 ide drives with grub on first drive, linux on second partition of second drive, ignores the separate /boot partition left over from fc3

Cool, I just figured it out. What I did was following:
- I took out hda, which is the harddisk with ext3, but no partitions
- I booted cd1 in rescue mode, and removed hda and changed hdb to hda
- I booted cd1 in upgrade mode, and told it to upgrade grub
- I put in the outtaken harddrive, but this time as slave and harddisk b.
- I booted up fedora and everything worked, except the nvidiadriver which generely don't like kernel swiching.

Thanks for your time and help.