Cannot use USB drives to install Windows 7 OR 8.1 in UEFI mode

[PlayerDot]

I just purchased an Acer Aspire E15 E5-571G-53B1 and it came without any OS.
I have two USB flash drives, one with Windows 7 and one with Windows 8.1 that I had made using Windows' bootable USB drive utility.

I tried all of the USB ports, 2 are 2.0 and 1 is 3.0, but none of them worked. I even changed the boot priority, but it always defaulted to the "No bootable device found" screen and forced me to turn my computer off.

No matter how much I fiddled around with the settings in my BIOS, it always resulted in the same error. So, I gave up, installed Windows 8.1 in Legacy mode, but obviously now I cannot switch back to UEFI mode, because it gives me the same problem a before.

Edit: This may be important: UEFI boot mode doesn't recognize ANY of my USB devices.

I searched the forums but I haven't found a resolution befitting my problem. Does anyone have any ideas what might be the cause and what can be done to fix it?

 

[Emerald]

Steps to create bootable Windows 7 USB for UEFI support and GPT partitions:

1. Open a command line in administrator mode
2. run DISKPART
3. type LIST DISK
4. Look for the disk number that represents your USB drive
5. type SELECT DISK # where # represents the number of your USB drive. Get this right or you will wipe a different drive out.
6. type CLEAN
7. type CREATE PARTITION PRIMARY
8. type SELECT PARTITION 1
9. type ACTIVE
10. type FORMAT quick fs=fat32
11. type assign
12. The drive should now be formatted and marked as active and fat32. Do not format the drive as NTFS or you will only be able to boot into the installer in BIOS mode.
13. Now you will need to copy the contents of the windows 7 install dvd to the USB with a regular copy paste from windows explorer.
14. Once this is done you will need to get a copy of the EFI boot manager firmware file from a computer that has windows 64 bit installed on a UEFI system.
15. This file is located in C:\Windows\Boot\EFI\bootmgfw.efi
16. On your USB (Let’s assume it’s drive E:\) look in E:\efi\microsoft\boot and copy this boot folder up one level so it sits in E:\efi\boot
17. Now copy the bootmgfw.efi file from your computer which has windows installed to this new E:\efi\boot folder and rename it to bootx64.efi


The same should work for Windows 8.x

 

[PlayerDot]

Steps to create bootable Windows 7 USB for UEFI support and GPT partitions:

1. Open a command line in administrator mode
2. run DISKPART
3. type LIST DISK
4. Look for the disk number that represents your USB drive
5. type SELECT DISK # where # represents the number of your USB drive. Get this right or you will wipe a different drive out.
6. type CLEAN
7. type CREATE PARTITION PRIMARY
8. type SELECT PARTITION 1
9. type ACTIVE
10. type FORMAT quick fs=fat32
11. type assign
12. The drive should now be formatted and marked as active and fat32. Do not format the drive as NTFS or you will only be able to boot into the installer in BIOS mode.
13. Now you will need to copy the contents of the windows 7 install dvd to the USB with a regular copy paste from windows explorer.
14. Once this is done you will need to get a copy of the EFI boot manager firmware file from a computer that has windows 64 bit installed on a UEFI system.
15. This file is located in C:\Windows\Boot\EFI\bootmgfw.efi
16. On your USB (Let’s assume it’s drive E:\) look in E:\efi\microsoft\boot and copy this boot folder up one level so it sits in E:\efi\boot
17. Now copy the bootmgfw.efi file from your computer which has windows installed to this new E:\efi\boot folder and rename it to bootx64.efi


The same should work for Windows 8.x

Is there anywhere I can find the .efi file online? Most of my friends upgraded to W10, the rest have old systems... and it seems that even these devices that have 8.1 Pre-installed have it in Legacy BIOS.