Windows IoT Core drivers
Intel BSP link as below for building IoT Core image for PICO-APL1.
https://downloadcenter.intel.com/download/25618 <- Please use the x64 version for Apollo lake
For the serial port driver (HS-UART), man can find the serial port driver in IoT Core BSP and it's provided by Microsoft
this link: https://docs.microsoft.com/en-us/windows-hardware/manufacture/iot/bsphardware#intel-bsps
BTW: AAEON has made a test version for Win10 IoT Core v1703 for PICO-APL1, follow the link below.