I corrupted /etc/shadow
I did a stupid thing, i played with the /etc/shadow file as root
and now nobody can log in. I have found an article that tells me how to fix it, but i need to be in run level 1. I don't know how to do that, so if anyone knows how to boot to run level 1 through grub in FC4, or a way to fix the shadow file, that would be greatly appreciated.