I Have a one problem , i buy a one PC for using in provisional for 2 Months for a clean Server. And no have a one driver for windows server 2008 r2.
i no have a USB DRIVER, Graphics Adapter and PCI Express controller.
Since this is being used in a Server type environment try posting your question at a more appropriate AMD Forum at Server Gurus : https://community.amd.com/t5/server-gurus/ct-p/amd-server-gurus
Also Windows Server 2008 isn't supported with updates anymore by Microsoft and is considered to be End Of Life.
The only OS compatible with Ryzen 3400G at AMD Download page is Windows 10 but is compatible with Windows 7 also in the Release notes.
In my opinion, Windows Server 2008 R2 might be to Out-Dated for the consumer 3400G processor.