Non-system Disk Error

MacBook Air 11-Inch, Late 2010

Processor - 1.6 GhZ Intel Core 2 Duo

Memory - 4 GB 1067 MHz DDR3

Graphics - NVIDIA GeForce 320M 256 MB

OS - macOS El Capitan, Version 10.11.6

I have previously Installed Windows 8 on my macbook air and removed it. Now I am trying to Install any version of Windows on my Macbook Air again. BootCamp did not allow my model to create a bootable USB, so I tweaked info.plist and added my model identifier in the USBSupportedModels list to make a bootable USB. (Installed Windows 8 using the same

BootCamp then displays - Create a Windows 7 or later install disk, Download the latest support software from Apple, and Install Windows 7 or later version. I then proceeded to download the Windows 10 x64 iso file and then used it to create a bootable usb along with support software installed in it. (16 GB HP USB).

I then proceeded to partition the drive using BootCamp's Install Windows 7 or later option, then BootCamp automatically restarted the macbook and should have displayed the install windows screen (like it did when I installed Windows 8 Previously a year ago), but instead booted to a black screen that displayed "Non-System Disk Press Any Key to Reboot". Tried rebooting with the option key, EFI Boot was displayed. Tried to install by using the bootcamp partition that was already created, but couldn't since Windows wouldn't let me - "The Selected Disk Has an MBR Partition Table. On EFI Systems, Windows Can Only Be Installed to GPT."

So I removed the BootCamp Partition and tried with another SanDisk 32 GB USB. Still gave the same "Non-System Disk" error. So I gave up on BootCamp.

I Tried to install Windows Directly through EFI Boot without Bootcamp from a tutorial that I found online at - http://fgimian.github.io/blog/2016/03/12/installing-windows-10-on-a-mac-without- bootcamp/ and used gdisk to change the hybrid MBR to protective MBR for Windows to let me delete the partitioned space and make a new NTFS volume to install it in (Otherwise it doesn't let you install windows on the partition and gives the previous MBR partition table message). And it failed the first time midway giving some error that just flashed and reboot the system. I tried a second time. And it worked. I installed Windows, I logged in to my Microsoft Account. My keyboard and trackpad both were working fine. I had to install the BootCamp drivers and get the BootCamp control Panel. I tried to install it from the Windows Support Software folder in the USB by running the setup.exe file only to get the message that BootCamp requires that I run Windows 7. Got insanely frustrated trying to search solutions online until I realised I could try running it in Windows 7 Compatibility mode. Ran it, drivers got installed and the system reboot and got stuck in a boot loop - Windows Logo appears, looping dots, and black screen, and reboot to white screen again. It went on and eventually landed in Repair mode and Recovery mode.

Hence, I removed the Windows Partition yet again. Thinking that it might be because my MacBook Air is too old to support Windows 10, I tried switching to installing Windows 7. Downloaded a Windows 7 x64 iso, and made another bootable USB Windows 7 disk, tried to install it using bootcamp itself. STILL gave me the frustrating Non-System Disk Error. I thought I could try EFI boot with windows 7. But the USB didn't even show up in the boot menu after long pressing the option key! Thinking it must be my USB, I tried another SanDisk USB as well. Still didn't show up. I even tried downloading the ISO again and doing it. STILL didn't show up on the boot menu. I heard that Windows 7 does support EFI but does it? Why is this? (One of my many questions.)

I tried to make a bootable USB through Unetbootin. Still didn't show up. I'm considering using RUFUS, but I'm really tired out. I need to know why all these problems have come up. What did I miss? Why can't I install using Bootcamp? And Why did I get stuck at the boot loop with Windows 10? And why couldn't I install BootCamp drivers directly, why did it require me using Windows 7? Do I have to modify something more? Please help me I have wasted two whole days for this.