Build: ASRock X470 Gaming ITX/ac (Combo-AM4 AGESA 220.127.116.11), AMD Radeon 5700XT, Ryzen 3700X, Corsair LPX Vengeance DDR4 3000 (8GBx2), Corsair SF750 (750W)
AMD Chipset driver: 1.07.07.0725
AMD GPU driver: 19.7.1, 19.7.2
Issue: During installation of 19.7.1/19.7.2 driver, Windows will crash and will be unable to load correctly. I then have to run DDU to get rid of the driver in Safe Mode and the default driver will be stable. I have done a fresh install of Windows 10 (1903). Issue does not occur with a Ryzen 2700X or Radeon VII installed for whatever reason.
Troubleshooting: I cleared CMOS after switching out the 2700X for the 3700X. I have run DDU in Safe Mode on a fresh Windows 10 (1903) install to uninstall drivers, and then tried installing only the 19.7.1 or 19.7.2 drivers (i.e., no Adrenalin software) but the PC will crash during install and will not boot into Windows. No error is generated in Windows Event Viewer. I am suspicious that either the motherboard or AMD driver are trying to force PCIe 4.0 when a Ryzen 3000 series CPU is present, which isn't supposed to be supported on the motherboard.
ASRock sent me a beta BIOS 3.41 (AGESA 18.104.22.168AB) for X470 Gaming ITX/ac. I can now install the AMD driver. There are also now options to set PCIe to Gen3 (which is the default setting).