Ubuntu – Trouble installing Windows 7 via USB

I've spent the better part of two days trying to solve this problem, and still I'm coming up empty.

I'm currently running Ubuntu 14.04 64-bit on an ASUS laptop. I don't have an optical drive, so I'm doing this install via USB.

The laptop originally came with Windows 8, but I wiped the whole thing and installed Ubuntu. In my moment of genius, I didn't create a Windows recovery disk, nor did I leave a Windows partition. Certainly not my finest hour.

Anyways, fast-forward to today, and I need to return to Windows for work reasons. I got a Windows 7 iso, a clean USB, and set to work creating a bootable USB. I first tried Startup Disk Creator, but that crashed upon opening.

Next I went with UNetbootin and Gparted. I followed multiple instructions online on how to setup the USB. Each instruction was the exact same. I had my bootable USB, so I shutdown and restarted my computer.

The first time I did this, BIOS didn't even recognize that I had a USB plugged in. I took it out and tried a few different times. No go.

I shredded the USB using sudo shred -v /dev/sdb1, reformatted as FAT32, and then started again. Same result.

Then I decided to skip Gparted and just try UNetbootin on its own. This time, BIOS recognized the USB, but still won't boot from it. Even when I set it as priority and disable the other HDD, nothing happens.

I have an iMac, so I tried creating a bootable USB that way, but again, nothing happens in BIOS. The USB is recognized, but nothing happens beyond that. I've formatted it as NTFS, FAT32, etc, but nothing happens.

I got another USB and put a fresh copy of Ubuntu 14.04 on it, figuring I'd boot from the USB, select 'Try Ubuntu', use Gparted to partition away a significant amount of Ubuntu, shut down, and then load my Windows USB.

Unfortunately, my computer doesn't even recognize that USB. Previously, I'd had to wipe Ubuntu and fresh install it (twice, actually) on this very laptop. I had zero problems doing that. For some reason, I can't fresh install Ubuntu anymore.

F2, F8, F10, F12, and DEL are the keys I know of for bootloading. F2, F12, and Del all bring me to BIOS, but the others do nothing. Previously, F8 worked perfectly as my "boot from disk" key, but it doesn't work anymore.

I'm nearing my wits end. I've done everything I can think of to get this working. I've tried multiple Windows ISOs, multiple Ubuntu ISOs, etc. Nothing works.

I know that the ISO isn't corrupted, because VirtualBox loads it just fine. However, my computer is too slow for that to be a permanent solution.

I'd like to wipe the whole HDD and install Windows, but I'm afraid that if I wipe Ubuntu, I may not be able to fresh install, since it doesn't appear to be letting me now.

Any suggestions would be great. Again, Startup Disk Creator (both versions) don't work. UNetbootin and UNetbootin 494 don't work. Gparted makes it so my computer can't even detect a USB. I'd love to get this working by this weekend if possible.

This is what I get when I use winusb:

grub-install: error: /media/winusb_target_1407472596_7189 doesn't look like an EFI partition. 
Error occurred! 
Syncing... 
/usr/bin/winusb: line 78: 11389 Terminated              while true; do
    sleep 0.05; echo 'pulse';
done
Cleaning... 
/usr/bin/winusb: line 78: 11577 Terminated              while true; do
    sleep 0.05; echo 'pulse';
done
Umounting and removing '/media/winusb_iso_1407472596_7189'... 
Umounting and removing '/media/winusb_target_1407472596_7189'...

Edit: I tried using WinUSB again after formatting the USB as FAT32. Here's the second message I received:

Installation failed !
Exit code: 512
Log:
Formating device...
Mounting...
mount: block device /home/zachary/Windows7Ultimate/Windows7Ultimate.iso is write-    protected, mounting read-only
Copying...
Installing grub...
Installing for x86_64-efi platform.
grub-install: error: /media/winusb_target_1407516090_3201 doesn't look like an EFI  partition.
Error occurred! 
Syncing... 
/usr/bin/winusb: line 78: 11389 Terminated              while true; do
    sleep 0.05; echo 'pulse';
done
Cleaning... 
/usr/bin/winusb: line 78: 11577 Terminated              while true; do
    sleep 0.05; echo 'pulse';
done
Umounting and removing '/media/winusb_iso_1407472596_7189'... 
Umounting and removing '/media/winusb_target_1407472596_7189'...