Driver Avermedia A857 Windows 7 64 Bits Link Guide

If the link above no longer works (the internet changes fast), search for as an alternative. Linux kernels up to 5.15 still support this chipset natively via the saa7134 module. You could then run a lightweight Linux VM on your Windows 7 machine.

: Ensure you run the installer as an Administrator to bypass User Account Control (UAC) restrictions common in Windows 7. Driver Avermedia A857 Windows 7 64 Bits LINK