Microsoft as well as AMD dropped support for Win8 a long time ago...and furnishes no new drivers for it. Use the free update to Win8.1 and have a fully supported computer.
like kingfish mentioned you should be on 8.1 for support. microsoft still sipports win 7 and 8.1 unless you have a ryzen or kaby lake cpu. you have an A8 so you will be fine with win8.1