Just bought a Viewsonic VP231wb 16:9 1920x1200 LCD monitor.  Can't
figure out how to get my Sony Vaio TX670 or my Dell D610 to output
1920x1200 to the monitor.  The Sony has a Intel 915BM/GMS chipset with
128MB of memory.  The Dell has the ATI Radeon X300.

I have downloaded and installed the Viewsonic device driver to both
machines.  I have turned on list all modes (even if not supported by
your monitor).

The Dell will show 1920x1200 as a resolution for the notebook monitor,
yet won't show that resolution for the external monitor. I have also
been able to get the external monitor to show much larger resolutions
than 1920x1200, yet within those lists, 1920x1200 wasn't listed.

On the Sony, I have downloaded the latest versions of the Intel
drivers, and got to see a resolution of 17xx x 13xx (2.3M).  Yet some
capabilities broke, so I rolled back to the orginal drivers.

Thanks for help that works!  Barry James

You can try using a freeware tool from EnTech Taiwan
MultiRes which enables you to easily access and alter the display settings
available through the current display drivers. If 1920x1200 is
available natively it will show and be easily switchable.
http://www.entechtaiwan.com/util/multires.shtm

Otherwise for making advanced custom resolutions you can use their
PowerStrip software which is try-before-you-buy and reasonably priced.
http://www.entechtaiwan.com/util/ps.shtm

Downloads are on the left side, click on the floppy disk icon.

Thanks for the suggestions.  Will try out when I get back from my
trip.  Thanks...Barry James

It may also be worth checking the drivers you have for the external
monitor.  If windows has picked out the wrong drivers, then it could
be limiting your resolution based on a lesser monitor.