I have been fighting with this external monitor resolution situation for the past two weeks. From the searches I've done, this is a very common issue; however, I have not found a solution. Every solution I have tried has been unsuccessful. I hope someone here can help.
Asus K50IJ laptop
Win 7 Home Premium 64 Bit SP1
Intel Core2Duo T6600
Mobile Intel 4 Series Express Chipset Family
Monitor is Samsung SC750_S24C750P connected with VGA cable (laptop does not have HDMI output)
I have reinstalled the drivers for the display adapter; current driver is 220.127.116.1169 from 10/4/2012
I have reinstalled the drivers for the monitor; current driver is 18.104.22.168 from 11/13/2012
Monitor is currently showing up as "Analog" in Device Manager; I have chosen "HDMI" and had the same results. Now & then I see "Generic PnP Monitor" in Device Manager; each time I see it I uninstall it.
Bottom line is this: settings keep bouncing all over the place. On a couple of rare occasions I have seen the image I want on the external monitor; when I close the lid on my computer (which is why I bought the external monitor - so I can have one larger image, not two), the resolution reverts to 1024x768. When I disconnect the external monitor I get the correct image and 16:9 ratio (1366x768) on my laptop screen; when I connect the external monitor I have two choices for resolution: 800x600 or 1024x768.
I have tried extended desktop setting; when I choose that setting the image on the monitor takes up about 60% of the real estate - the rest is black. When I close the lid on the laptop (in extended screen mode), the image on the monitor is much larger, but still has two black bars on the side and is severely distorted - horizontally compressed.
I went to Intel's Graphics Properties tool and set a custom resolution to 1920x1080 - 60Hz - 32 bit - recommended by Samsung for their monitor. Result is 7 choices for resolution, none tagged "recommended" and the highest being 1366x768. I can live with 1280x720; when I choose that resolution or anything higher the laptop screen looks great but the image on the external monitor covers 1/4 of the screen - the rest is black. Resetting external monitor doesn't change anything. Restarting computer doesn't help. Unplugging/reconnecting monitor doesn't help. I've tried this routine a dozen times.
One additional note: I was using this with a 4:3 external monitor in the past - is it possible there is a file somewhere that is forcing every external monitor to the older settings when I attach it? I can have perfect settings on my laptop screen, but as soon as I plug in the external monitor everything goes wacko.
I really need to use the external monitor, and I need the image to be proportional. Is there any way to accomplish this? Right now I have only two options: not use the external display (right now it's off), or use it with a severely distorted image. The only other option I have is to purchase a new computer, and I'd really like to avoid that if I can!!
Thanks in advance.