American Megatrends is a BIOS manufacturer last I checked. the BIOS has to run before the OS. The BIOS checks and verifies the Basic Input/Output System, checks the memory and governs many hardware settings. no BIOS no Windows.
if it is booting into the BIOS every time requiring you to exit, that is not normal. there may be a setting in the BIOS enabling this, or the keyboard may be shorting/have a stuck key.
I would try with a different keyboard (if USB keyboard (and only USB keyboards) you can boot with no keyboard and plug it in when windows boots)