? 
Liked by
Blank Screen After Installing Windows 7: Fix
6 April 2009 @ 12pm
After
installing Windows 7, you may experience an issue in which the
screen(s) becomes completely blank directly after startup. This problem
primarily affects multiple-monitor setups.
Fix In order to fix this issue, you first need to regain
access to onscreen display. You can do this by either booting in safe
mode (tap the F8 key on your keyboard repeatedly as the computer is
starting up) or by temporarily disconnecting all but one of your
monitors.
After you have started up and have access to your display, you will need to create a .bat file that kills the dwm process at startup. Follow these steps.
- Launch the Notepad application and create a new text document
- Type the following text into the document: taskkill /F /IM dwm.exe
- Save the file as displayfix.bat
- Copy this file to C:/ProgramData/Microsoft/Windows/Start Menu/Programs/Startup
- Restart
After you restart, Windows Aero may be disabled. To turn Aero back
on, right-click on the desktop and select “Troubleshoot problems with
transparency and other Aero effects” then enable Aero.
source: http://windowsfixup.com/2009/04/blank-screen-after-installing-windows-7-fix/