Start the PC is SafeMode, uninstall the graphics driver, restart the PC. search driver on net for windows 7 64 Bit Driver, may be you installed driver for 32 Bit. so it creates problem.
Im sure i have the driver for 64 Bit. Its downloaded from intels download center. I got the same result in windows 7 32 bit also. Black screen after the windows boot screen. After uninstalling the driver in safe mode then i can boot up again.