Windows 8.1 supports I2C Touchpad, but you need your manufacturer's GPIO and I2C drivers.
You can get latest AMD drivers from 2022 on 7 and 8.1 by using the iCafe drivers. https://www.amd.com/zh-hans/support/kb/release-notes/icafe-windows-7-driver
Sadly my laptop's RTL8822CE Wi-Fi Card doesn't support Windows 7 or 8.1 (I tried on both) even with an inf mod, so it would be nice to get that working.