The BIOS and drivers for your son's system can be downloaded from the motherboard manufacturer's website. Typically these are included on a CD that comes in the box, but you can certainly download them and copy to a USB flash drive if you prefer.
What is the motherboard make and model?
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT