If you Can StartX Only by the root User but You Can Not StartX by the Normal Users the this Tip Should Solve the Problem.
Solution:

1. Configure/Re-Configure the X Server

   X -configure

   mv /root/xorg.conf /etc/X11

2. Make/Re-Make a Proper .xinitrc

   mv ~/.xinitrc ~/.xinitrc.back

   cp /etc/skel/.xinitrc ~/.xinitrc