I am not familiar with windows 8 but you can always use the good old command line ( or edit the Dolphin shortcut and add the proper command line argument. It looks like this:
Dolphin.exe -e "path to your iso here.iso"
Dolphin.exe -e "path to your iso here.iso"
i5-8600K @ 4.5 GHz
GeForce GTX 1080 SC2
ASRock Z370 Taichi LGA 1151
CORSAIR Vengeance LPX 16GB 2400 DDR4
SAMSUNG 970 EVO M.2 500GB PCIe SSD
Indigo Xtreme TIM
Phanteks Pro ES614P Black Steel Case
EVGA SuperNOVA 750W PSU
Windows 10 64-bit
GeForce GTX 1080 SC2
ASRock Z370 Taichi LGA 1151
CORSAIR Vengeance LPX 16GB 2400 DDR4
SAMSUNG 970 EVO M.2 500GB PCIe SSD
Indigo Xtreme TIM
Phanteks Pro ES614P Black Steel Case
EVGA SuperNOVA 750W PSU
Windows 10 64-bit