crash, kde3, Xserver does not start any more

Hello I have installed Kubuntu 10.04 with trinity 3.5.11 (I think) on a X60 Thinkpad Laptop. This morning the xerver freezed and I had to reboot, I got a graphical login, could login, kde3 started, however the hard disk was in read only mode. So I rebooted again, this time it took almost 15 min to reboot, a sign that some hard disk problem occurred; (I have the jfs file system.) Anyhow finally the machine booted again successfully, I got a graphical login but now I could *NOT* login, the password was accepted but instead the graphical login screen reappeared. I could login on a terminal though. So I thought maybe the xorg.conf file was damaged. But this Kubuntu version does not have a xorg file anymore, as google told me. So what can I do? (1) sudo dpkg-reconfigure xserver-org ??? (2) sudo X -configure? (3) sudo dexconfiure -o xorg.con?? Any help is strongly appreciated, because the only other solution it to try a _complete_ reinstall. thanks Uwe Brauer