If you get another terminal by pressing Ctrl+Alt+F1 ( normally X window is on F7 so you should have F1, F2, F3, ecc.) loggin in as root you can try to reconfigure X running Xconfigurator. Instead if your computer is really blocking ( curious ), you can try, at the lilo boot, to type <<linux single>> ( if it asks a password type the root password ).
At the prompt edit the file /etc/inittab ( typing
<<vi /etc/inittab >> and look for a line containing <<id:5:initdefault:>> replace the 5 with a 3 ( it makes the default init 3 witch doesn't start X ) like this <<id:3:initdefault:>> and then reboot pressing Ctrl+Alt+Del
or typing <<shutdown>>.
If the computer starts normally now try to reconfigure X running <<Xconfigurator>> choosing the right graphic card, a vga resolution ( 640x480 ) initially and have a look.
I hope i did something!
Masi