Formatting is irreversible. Back up your files before changing boot priorities.
Formatting a drive from the BIOS is a common misconception. You cannot actually format a storage drive directly inside the BIOS or UEFI interface because those systems lack the file management tools required to write a file system (like NTFS or FAT32) to a disk. how to format drive from bios
Download this from Microsoft to create a bootable USB. Formatting is irreversible