:replace everything with
<nowiki>              Section "Monitor"
            Identifier "Monitor0"
            HorizSync 31-81
            VertRefresh 56-75
       EndSection
 
       Section "Device"
            Identifier "Card0"
            Driver "vesa"
       EndSection
 
       Section "Screen"
            Identifier "Screen0"
            Monitor "Monitor0"
       EndSection
</nowiki>
:save and close xorg.conf