Generally, most bios let you reset the bios to the factory defaults from within the bios itself. The other methods you mention are usually not required.
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Sometimes the simplest things are the furthest away. 
Sometimes the obvious things are the furthest away.
Sounds like you deleted your Windows bootloader, try this link to repair:
https://www.easeus.com/partition-manager-software/fix-uefi-boot-in-windows-10-8-7.html