How to Fresh Install Windows 7 on Windows UEFI Boot Mode
Many people want to downgrade Windows 8 to Windows 7 because of application problem, compatibility issue or just don't like Windows 8.
Follow the steps below and you can downgrade Windows 8. First, making sure your computer hardware have Windows 7 drivers before proceed.
Make your DVD drive bootable
You may notice when you insert your Windows 7 installation disc and reboot your computer, it automatically boot back to Windows 8. If you purchased your computer that had windows 8 pre-installed already, then you need to go to Settings > Change PC Settings > General > Advanced Start Up. On the next screen select Troubleshoot > Advanced Options > UEFI Firmware Settings. Disable the secure boot. Restart and boot off dvd.
Installation of Windows 7 didn't work
So you booted via the Windows 7 disc and during the loading files, it restarted or failed. This is caused by the UEFI boot problem.
Solution: BIOS Setup
Restart your computer and press F2 or Del to go into the BIOS setup screen.
Set CSM: Enabled
Boot Device: UEFI and Legacy
Boot Device #1: Windows Boot Manager
Save and Exit the BIOS. Windows 7 installation should be working normally.