Kernel installation demolished Grub :(
 

I've only installed an (xen) kernel-image (2.6.17.2) with apt-get. This changed the whole menue.list, created the initrd and ... demolished Grub. Now its not possible anymore to boot even not grub bootscreen can be seen.

The file: stage1 and stage2 were missing in /boot/grub and if copied them back: cp /usr/lib/grub/i386-pc/stage1 /boot/grub
But still grub will not show its bootmenue.

Already grub was new installed by using grub-install - but no bootscreen.

What to do?

You can boot from a rescue CD or Knoppix or something like that and try to repair the system.