NEW ISSUE? Windows 7 Boot Camp No bootable device

Hello, I have been having a problem attempting to set up windows 7 on Sierra 10.12.3 Macbook Pro Late 2011.

I've been reading different opinions on what works on this new IOS. When I look at the main support website it says "Mac computers using macOS Sierra 10.12 support new installations of Windows 10, Windows 8.1, and Windows 7 only."

But when starting to run boot camp I don't get the option Create a Version Install Disk. So I watched a video that edited the boot camp text file to show the installation option.I then download the install disk to my flashdrive. Then it wouldn't let me download the support software directly from boot camp so I took the 5.1.5621 version file it recommended from my computer, added it to my flash drive. Then when partitioning, it restarted as expected until I got the black background with the white text saying No Bootable device insert boot disk and press any key.

This is where I am stuck, I look all over the help forums some say use a different disk drive, or I read Sierra does not support windows 7. I feel like the error is from changing the text file in the boot camp content in order to create the drive installation option. I'm just confused and most of the information that I see relevant is outdated any help is appreciated thanks.