I have an Intel DZ68BC motherboard with Intel HD graphics card using two monitors (on DVI and on HDMI » VGA). My friend asked me to test if his NVIDIA graphics card works well on my computer (at his it was doing some trouble), so I inserted it in my computer, installed the NVIDIA driver and it worked quite well. Then I removed it, uninstalled everything NVIDIA-related I could find and switched monitors back to my Intel card.
Since then after every system start/restart, the system sees only monitor on HDMI » VGA connector, completely ignoring the DVI monitor.
I noticed that installing the Intel video drivers causes the system to recognize the second monitor if I don't immediately reboot. After a reboot, the system recognizes only the HDMI » VGA monitor.
I also tried starting in safe-mode and using DriveSweeper to remove the remains of NVIDIA drivers. While it seems that some drivers were removed, the situation didn't change. Now I am out of ideas and I really wouldn't like to reinstall the system (again...).
I also tried restoring the system to the state before this whole story, but it also didn't change anything.
I am still trying to troubleshoot this problem. The only point that I could start was driver re-instalation. I traced down the part that restores right settings to a call:
C:\Users\Jarek\Desktop\GFX_Win7_64_22.214.171.12496\x64\Drv64.exe -driverinf "C:\Users\Jarek\Desktop\GFX_Win7_64_126.96.36.19996\Graphics\igdlh64.inf" -flags 20 -keypath "Software\Intel\Difx64"
This call fixes my displays, and as workaround, I will add it for now to my autorun. I am still looking for better solution anyway...
Using DriverView i made a list of currently used drivers both before and after fixing my display using above command. Then i compared logs:
- No drivers were removed by fixing command.
- Drivers added by fixing command:
- MS Remote Access serial network driver (asyncmac.sys)
- security processor (spsys.sys)
- Drivers that changed base address (indicates driver-reload?)
- Canonical Display Driver (cdd.dll)
- Intel Graphics Kernel Mode Driver (igdkmd64.sys)
- Monitor Driver (monitor.sys)
Added drivers seem rather unrelated to the problem to me, reloaded drivers are just a cnsequence of installing new driver file so there is not much to go here... I really cannot make heads or tails out of it...
I made clean install of Windows 7, and guess what? It still doesn't work... After some more googling it seems that it's most likely faulty driver - after I installed it, HDMI went down... If i didn't have additional VGA monitor, I would probably conclude that my graphic card doesn't work at all. I really wonder how did I get it working in the first place. I remember installing Windows 7 without big problems. The drivers I used before were the same as used now, and I disabled automatic updates while installing W7, in case some of them are causing trouble - without much success.
I found out that it's enough to disable and re-enable your graphic card to get it working. You can use DevCon.exe (don't use the old one that you can download directly, it's veeeery old. Please extract it from WDDK, from archive WDK\setuptools_x64fre_cab001.cab). After you find out right Hardware ID for your video card, it's best to create small script (.bat file) using
devcon restart <HwID> and add it to logon scripts ('gpedit.msc' -> Computer configuration -> Windows settings -> Scripts).
While it's a hack, it works so well, that you won't even notice it was there. And I am avoiding constant re-installing drivers (in my old method) which is quite significant on my SSD drive I think ;)