Can't set resolution greater than 800X600

[peterv6]

I'm running Ubuntu 9.10 Desktop with a Dell 19" monitor. It's a dual boot with Windows XP Pro. The resolution in Windows is 1024X768. In Ubuntu, however, the max setting allowed is 800x600. The detect monitors button also doesn't do anything. Can anyone tell me how to configure the system so that it recognizes the correct monitor? I have a root account activated, so I can do anything on both the gui & terminal, but I don't know how to configure the hardward. Please help if you can.
Thanks,
Peter V.

[NetBoy_Pilot]

You will want to create/edit the xorg.conf file.
This file is located at /etc/X11/xorg.conf

Here is the xorg.conf I use. Note that you will need to get the horiz and vert refresh rates for your particular monitor.

-Net-

# xorg.conf (X.Org 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 xorg.conf manual page.
# (Type "man 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.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# 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 "Device"
Identifier "Configured Video Device"'
EndSection

Section "Monitor"
Identifier "Gateway VX900"
HorizSync 31-95
VertRefresh 50-160
EndSection

Section "Screen"
Identifier "Default Screen"
Monitor "Gateway VX900"
Device "Configured Video Device"
DefaultDepth 24
Subsection "Display"
Depth 8 Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubsection
Subsection "Display"
Depth 16 Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubsection
Subsection "Display"
Depth 24 Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubsection
EndSection

[khelben1979]

First it would be interesting to know something about your computer hardware:

lspci

Depending on your hardware graphic card/chipset + graphics driver it will determine your possibilities on getting a higher video resolution.

Your system is most likely configured to use slow open source video drivers from default, it should, however, not prevent you from using a higher video resolution such as 1024x768 since Windows XP allowed it, but I cannot promise anything of course, it's up to the graphics driver to decide.