Dell owners, for System and Video BIOS's see bottom of page.

Dell Inspiron and M50 owners with UXGA (1600x1200) screens

I have discovered that certain UXGA screens have problems with Resolutions.

Inspiron 8000 and 8100 with UXGA screens (1600x1200), these older Inspirons with certain LCD panels, can't get past 800x600x4 with most detonators.
Not all of them do it, only certain machines, I haven't had the time to test which make of Panel is to blame.
The only solution (if you can call it that) is to try until a certain Detonator works for you. Not ideal but better than nothing.

Inspiron 8200 and M50 with Ultra Sharp UXGA screens (1600x1200), now with these screens, I've tracked it down to the Samsung Ultra sharp LCD panel causing the display not getting to max resolution.
The Sharp Ultra sharp LCD panel works just fine. There is no fix for this, but like the i8000 and i8100 just try drivers until you find one that works. (not many do)
For the owners of the above with a Quadro4 700goGL card can safely use my 42.57 INF this works.

If you have one of the above Panels and can get a certain detonator to work for your machine, give me a yell and I'll list the detonators here for others.

The whole problem with all this is the EDID being read or interpreted wrong.
This is what WinXP reads from the LCD panel (i8200/M50) or from nVidia lookup tables (i8000/8100).
I don't know of a fix, and it gets very time consuming and complicated, especially not having an UXGA screen my self.
But it is just matter of trying until you find a working Driver.

System/Video BIOS updates.

Below are links for Dell laptop BIOS and Video Driver updates. Make sure you have the latest System BIOS and Video BIOS (if available).
All downloads are from The Asia pacific Dell server, this seems to be the better place for International downloads as the US site takes you to Premier support only for US machines.