Reinstalling Linux

Hello everybody.

I don't know what settings did i do to my computer but i know which are the consequences:

- after booting there is available only one shell (alt+F2,or alt+F3 give me no other shell);
- now my hostname is none ! ( i mean it appears root@(none) and this very strange ; first my hostname was darkstar so... root@darkstar )
-crtl+alt+del transmit no signal ! and to stop my pc i have to type /sbin/halt
-when i try to mount my floppy ( exp: mount /dev/fd0 /mnt/floppy ) it requires me the file system ;
-startx doesnt work; error message appears (settings are incorrect)

And i don't know why ? (first i made some wrong settings for my video card and i lost my graphic interface ; then i tried to repair/recover it using xf86config ; after playing with xf86config my problems appeared and i don't know why! )
Can anybody give me some help ?

-thats why now i am reinstalling linux

Since you only have one console I draw the conclusion that you are in single user mode.
Try running telinit 3
Do you get more consoles?
If so then you can try runlevel 5, the graphical. telinit 5
The reason you get into single user mode might be a setting in the /etc/inittab file.
Check for the line
id:1:initdefault:

If the number is 1 then change to 5 for starting X on boot.