Not sure I follow. In my Device Manager there's two monitors listed:

Generic Non-PnP Monitor

Generic PnP Monitor

I double clicked the "Non-PnP" one and followed your instructions to the best of my ability. I have Windows 7 so I wasn't presented with the exact same options. Instead I did it like this (after the "Click the Update Driver button" step:

* Browse my computer for driver software

* Clicked "Browse" button

* Navigated to C:\Dell\Drivers\R91058

* Clicked "Next"

Result was this from Windows:

"Windows has determined the ddriver software for your device is up to date."

I see no change after this. The monitor is still identified as a "Generic Non-PnP Monitor" and I can't increase the resolution beyond 1024x768.

Did I do anything wrong?

Moggel,

* The 2405FPW inf file is here: ftp://ftp.dell.com/monitors/R91058.EXE
* Download/Save the file to your desktop
* Double-click the file
* It will extract to C:\Dell\Drivers\R91058\

* Open the Device Manager
* Click the icon left of Monitors
* Double click the monitor listed
* Click the Driver tab
* Click the Update Driver button
* Click No, not at this time
* Click Next
* Dot Install from a list or specific location
* Click Next
* Click Don't search. I will choose the driver to install
* Click Next
* Click Have Disk
* Click Browse and navigate to where the three files are now (C:\Dell\Drivers\R91058\)
* Click the monitor inf file
* Click Open
* Click OK
* Click Next
* Click Finish
* Now the Device Manager- Monitors should show your monitor. Once done, exit the Device Manager
* Change the desktop resolution to 1920x1200

I have done some more investigation...

I have second Windows instance (dual boot) so I switched over to that one and saw the exact same result: The monitor is not being recognized as a DELL (just a non-PnP monitor). That, I believe, rules out the driver theory doesn't it (it's unlikely that the driver has failed on two independent windows configurations isn't it)?

I then tried to plug it in as a secondary monitor to my laptop, using a VGA cable. The laptop (also Windows 7) does recognize it as a DELL 2405FPW and allows changing resolution too.

Any conclusions to be drawn from this? Is there something physically wrong with the DVI interface perhaps?

Ok. The driver inf I presented was for XP. Dell never wrote a Windows 7 specific inf for this monitor. So it should appear as Generic PnP Monitor. But not as Generic non-PnP. Test a VGA to VGA cable.

Unless I misunderstand I already tested VGA (see my last post above) and it seems to work ok. My laptop, that I used to conduct the experiment, and that is also Windows 7 x64, do list the monitor as "DELL 2405FPW" (not "Generic PnP Monitor") and all looks ok. Unfortunately VGA is not an option with my desktop box, that I use the monitor with, as the graphics cards are too modern to support it. DVI has been working fine before so something seems to have happened recently, I just can't figure out what it is.

I have never heard of a monitor DVI port failing but it could be possible in your case. We do not have monitor internal parts so if it has failed there is no fix for it. Can you test the 2405FPW DVI on another computers DVI out?
Fusion 25773473

I too have the same problem on a Win7 - 64bit using AMD Radeon HD63050 video card.  Monitor 1 - listed resolution of 1920x1200 and Monitor 2 - listed 1600 x 1200 (which is the max).  Is there any fix for this?

City of SJ,

What specific monitors are connected to what specific ports on the video card using what cabling?

I have (2) Dell 2405 FPW.

Please test each monitor by themselves on all of the Radeon DVI ports. No dual monitor setup.

By themselves, does the operating system recognize in the Device Manager as 2405FPW? Does the resolution show 1920x1200?