Please,the question with "xhost +localhost"
 

after "xhost +localhost"
reboot
login
i can't run "startx"
what can i do

Howzit

Goto you /etc/hosts file and check if u have the following
127.0.0.1 localhost.localdomain localhost

if not change to the above and try again

chow

thanks
but i /etc/hosts file is the same as that you said
but i can't run "startx"

Howzit

What does u'r /var/log/XFree86.0.log say and also check what /var/log/messages file say. In both cases check the end of these files and if possible post the errors.

chow

after reboot do the xhost+ again try to run your application again

you've still not said WHY you can't run startx. maybe your T key has fallen of? ;)

after reboot i can't do the xhost+*
the message is
xhost :unable to open display ""

do startx
some message:
xterm:fatal IO error ...
xinit :connection to X server ...

i can't understand "the Xserver"
sometimes i can do startx
but i can't control anything
i can only do ctrl+alt+backspace
what's wrong?