اگه کارت گرافیکت nvidia هستش ابتدا از فایل xorg.conf بک آپ بگیر و این رو جاش بذار
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 1.0 (buildmeister@builder75) Tue Dec 8 21:07:34 PST 2009
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder3) Mon Feb 26 23:38:46 PST 2007
# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the /etc/X11/xorg.conf manual page.
# (Type "man /etc/X11/xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg
Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
Option "AIGLX" "on"
Option "Xinerama" "0"
EndSection
Section "Files"
# path to defoma fonts
FontPath "/usr/share/fonts/X11/misc"
FontPath "/usr/share/fonts/X11/100dpi:unscaled"
FontPath "/usr/share/fonts/X11/75dpi:unscaled"
FontPath "/usr/share/fonts/X11/Type1"
FontPath "/usr/local/share/fonts"
EndSection
Section "Module"
Load "bitmap"
Load "dbe"
Load "ddc"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "record"
Load "v4l"
Load "vbe"
EndSection
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc104"
Option "XkbLayout" "us"
EndSection
Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ImPS/2"
Option "Emulate3Buttons" "true"
EndSection
Section "Monitor"
Identifier "585E"
HorizSync 30.0 - 68.0
VertRefresh 50.0 - 85.0
Option "DPMS"
EndSection
Section "Monitor"
Identifier "Monitor0"
VendorName "Unknown"
ModelName "Samsung SyncMaster"
HorizSync 30.0 - 81.0
VertRefresh 56.0 - 75.0
EndSection
Section "Device"
Identifier "nVidia Corporation NV44 [GeForce 6200 TurboCache(TM)]"
Driver "nvidia"
Option "AllowGLXWithComposite" "true"
Option "RenderAccel" "true"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce 6200 TurboCache(TM)"
EndSection
Section "Screen"
Identifier "Default Screen"
Device "nVidia Corporation NV44 [GeForce 6200 TurboCache(TM)]"
Monitor "585E"
DefaultDepth 24
Option "XAANoOffscreenPixmaps"
Option "AddARGBGLXVisuals" "true"
SubSection "Display"
Depth 1
Modes "1200x800" "1152x864" "1152x768" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1440x900" "1440x900" "1440x900" "1440x900" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1440x900" "1440x900" "1440x900" "1440x900" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1440x900" "1440x900" "1440x900" "1440x900" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1440x900" "1440x900" "1440x900" "1440x900" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1440x900" "1440x900" "1440x900" "1440x900" "800x600" "640x480"
EndSubSection
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "TwinView" "0"
Option "TwinViewXineramaInfoOrder" "CRT-0"
Option "metamodes" "nvidia-auto-select +0+0; 1024x768 +0+0; 800x600 +0+0; 640x480 +0+0"
SubSection "Display"
Depth 24
EndSubSection
EndSection
Section "Extensions"
Option "Composite" "Enable"
EndSection