This was one of the most frustrating challenges I’ve experienced since I installed the home theater PC system, mainly because I initially had no clue what was causing the problem, and it’s happened twice in about 6 months. This challenge likely will only occur if you have an older monitor as your second monitor, in addition to your HDTV.
A quick background with the solution in bold at the bottom:
I have an hp pavilion pc windows 7 with a radeon 5770, connected to two displays. I started up the computer about 4 months ago. The two displays are:
1)a pioneer vsx 1020 a/v receiver (in turn connected to my toshiba hdtv) via hdmi
2)an old (2001 or so) acer 1916 monitor
Everything was working fine for a while. I could control music selection (pandora) on the acer monitor while just having the a/v receiver on and not the hdtv, and it would be in dual display mode (both hdtv and monitor would default to 1280X1024 resolution—lowest resolution between the pair). Or I could extend displays and view hdtv in full ~1920X1000 hd resolution. When I chose extended display settings, it would recognize the acer monitor and recommend the correct resolution per this image: http://www.greenandtheblue.com/homet…desktop_PC.png.
Just a few days ago, I turned on the a/v receiver and the acer monitor (without turning on the hdtv) and the display was just the background and the resolution was too large on the acer monitor. I checked devices and now it shows “generic non pnp monitor”. Equally confusing, in the catalyst control center settings, it shows the correct monitor (whereas windows config shows generic pnp) but it shows max reported res as 1600 X 1200 which is not correct.
I don’t have a problem when I turn on the acer monitor, a/v receiver AND the hdtv…the settings go back to dual display and the resolution is fine. It’s a problem b/c I don’t want to have to turn on the hdtv and acer monitor just to control the pandora, etc and listen to music via the receiver.
Eventually, I did two things in order which fixed the monitor.
1) Unplugged power and connection to monitor
2) Reinstalled HP monitor drivers per HP Recovery Manager program by searching for Recovery Manager on the Start menu.
After these two steps, the Windows “Screen Resolution” menu recognized my monitor as an “Acer AL 1916″ instead of a “Generic Non PnP Monitor”
I believe the problem occurred when either Windows or HP made a significant update in my computer, which seems to occur every several months. This is a minor inconvenience in the grand scheme of things.