System found unauthorized changes on the firmware

Solution 1:

Windows 7 does not support Secure Boot, leave it off.

"Secure Boot is a security standard developed by members of the PC industry to help make sure that your PC boots using only software that is trusted by the PC manufacturer."

When the PC starts, the firmware checks the signature of each piece of boot software, including firmware drivers (Option ROMs) and the operating system. If the signatures are good, the PC boots, and the firmware gives control to the operating system."

The following versions of Windows support Secure Boot: Windows 8.1, Windows Server 2012 R2, Windows RT 8.1, Windows 8, Windows Server 2012, and Windows RT."

https://technet.microsoft.com/en-us/library/hh824987.aspx