Reboot and select Proper Boot device

[J1mjom]

Motherboard: Gigabyte A520I AC

RAM: TEAMGROUP Elite DDR4 64GB Kit (2 x 32GB) 3200MHz (PC4-25600) CL22 Unbuffered

Storage: Silicon Power 1TB - NVMe M.2 PCIe Gen3x4 2280 TLC SSD

Case: Fractal Design Define Nano S

Graphics Card: Sapphire Pulse Radeon RX 5500 XT

Processor: Ryzen 9 3900 X using stock AMD cooler 

PSU: EVGA Supernova 550 GM (550 W) 80 Plus Gold Fully Modular

 

Hello! So I finally finished my building a PC for my friend. It's the first time I've ever built one. However, whenever I plugged in an HDMI to my GPU for the first time, the monitor showed the "reboot and select proper boot device or insert Boot Media in selected Boot Device". It didn't show me a POST screen or anything. I wasn't too surprised as I hadn't installed Windows yet, but when I tried to get to the BIOS from there by pressing delete as that is the Key to get to the BIOS on a Gigabyte Motherboard, it just repeated the same message. I won't be able to install Windows without getting to the BIOS. Is there something I need to do/should have done?

[Oshino Shinobu]

Shutdown the PC and turn it back on. Hold down the Delete key while it's powering on and you should get into the BIOS. 

[paddy-stone]

make a bootable USB of the OS you want to install and plug it in. AFAICR most UEFI should detect the boot device automatically and start the install.