whole system is read-only

[mitjab]

I start ubuntu and i see that my whole system is read only. I can not get to GDM, i cannot use apt-get, nothing.

I can not change any file becouse my whole system is read only.

Last thing i make is that i add userquota in /etc/fstab maybe this is problem, but i can not remove it becouse system is ro.

How is this possible, how can i make that it will be writtable?

I use LiveCD and open mounted disk and try to run fsck but nothing happend. can i run fsck from live CD? Can i chroot to ubuntu install disk?