It may be failng to load a Device Driver
. Follow these steps to enter Device Manager to uninstall any devices which show to be in error, to see if Installation will complete: Device Manager - Access During Windows 7 Installation
Unplug all peripherals and other HD's.
If this fails, reset the CMOS: Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOS
Set SATA controller to AHCI.
Wipe the HD first to Clean the boot sector: SSD - HDD Optimize for Windows Reinstallation
Where did you get Windows 7? Is this a known-good installation DVD? If not and you burned it yourself, burn another using ImgBurn at 4x speed. Next try writing to flash stick using Universal USB Installer
with Windows 7 in dropdown menu.