Boot problem after switching from Ubuntu. "The system has found unauthorized changes on the firmware, OS or UEFI drivers"

[Turtled]

Hey people!

So recently I finally made the switch from Ubuntu to Windows 7. During the process I had to reformat the disk with a live Ubuntu disk in order for Windows to install, but other than that everything went smoothly. So I've been gone for about a week and when I got back I found the following error message:

 The system found unauthorized changes on the firmware, operating system or UEFI drivers.

Press [N] to run the next boot device,
or enter directly to BIOS setup if there are no other boot devices installed.
Go to BIOS setup > advanced > Boot and change the current boot device into other secured boot devices.

If I press N it goes to a new screen with this error message:

SYSLINUX 6.03 EDD 2014-10-06 Copyright (C) 1994-2014 H. Peter Anvin et all

Failed to load idlinux.c32
Boot failed: please change disks and press any key to continue.

When I press any key it basically just loops, ofc.

The following are all the entries in the boot order BIOS page:

P1: ASUS    DRW-24F1ST  c
P0: WDC WD10EZEX-22MFCA0    (953869MB)
SanDisk     (239168MB)
Windows Boot Manager (P1:WDC WD10EZEX-22MFCA0)
UEFI: SanDisk (239168MB)

I've tried them all but they all do the same SYSLINUX error page.

I've restarted my computer before after installing Windows and this didn't happen, no idea why it's happening now after I was gone for a week. I probably should have remembered to shut it down while I was away.

So, any smart, sexy folks out there that know what's going on here?
I'm assuming it's something to do with which format I used while partitioning (which was sda1 if I remember correctly).

Thanks!

 

[Turtled]

Found the solution. I changed secure boot from "Windows UEFI" to "Other OS"