Recently my NVIDIA GeForce8400GS graphics card with dual monitors (ASUS MS227 vga/DVI-D) on a Windows 7 64-bit PC was working great!
Then, I downloaded a Keil C Compiler (MDK420.EXE) and ran the install. At the point when USB drivers were installed, my second screen (DVI-D) went black. I have tried uninstalling the Keil software, uninstalling and reinstalling the NVIDIA driver (270.61), swapping monitors, booting with just a DVI monitor connected, and so on. Still, the DVI monitor is not recognized.
Keil's response is : "We have had thousands of downloads and no problems"
To NVIDIA's credit they are working with me, asking that I try simple experiments. What I was really hoping for is some way to inspect the PlugnPlay registry values, as I assume that if a monitor is not detected, the problem lies there. Windows 7 has a new way of doing dealing with displays (QueryDisplayConfig and SetDisplayConfig), so not too surprising that there could be a new problem.
I advise you to unplug any secondary DVI screen before you install this program!
I think you'd at least need to demonstrate it on another PC.
It could still be that the fault lies elsewhere, and it's just the Keil installation that happens to let it manifest...
But I agree that Keil should be more cooperative.
Is it the installer, or the actual Keil tools?
The problem occurs exactly at the point of USB driver installation. This is an especially difficult bug to fix and with such an isolated case will be impossible to command resources. My purpose in posting is really just to warn Win7 64 users about this so they can avoid the problem.