To install macOS on your Windows PC with the Asus M5A78L-M LX V2 motherboard, you need to enter the BIOS settings and change a few options. First, enable "SATA Mode" to AHCI to ensure proper disk access. Additionally, disable "Secure Boot" and "Fast Boot" if these options are available. Finally, make sure your boot priority is set to the drive where you plan to install macOS.