We've already reported about this before, but sticking with Windows 7 is definitely not an option if you want to keep your system up to date. In 2016, Microsoft stopped providing support for new processors for Windows 7 and the result is that new platforms are not compatible with the aging operating system.
As such, it isn't really a surprise that AMD's new Raven Ridge APUs can't boot on systems with Windows 7. PC Games Hardware reports someone gave it a try and discovered that both the AMD Ryzen 5 2400G and Ryzen 3 2200G will result in a blue screen of death (BSOD) during the boot process.
Neither an ASRock nor a Gigabyte motherboard managed to boot Windows 7. ASRock's support team says a new energy management feature of Raven Ridge causes the problem. Without proper drivers you can't boot the system.
This news also implies the upcoming Ryzen 2000 processors won't be compatible with Windows 7 either.
The only solution is to upgrade to Windows 10, just like Microsoft intended.