If you canโt from Bios, use nvidia/amd control panel and set all exes in fivereborn to launch with high performance gpu card.
Next, uncheck read-only for all files in the rof folder.
Last thing you can do, make sure all exes in fivereborn are set to run as administrator and check compatiblity mode windows vista service pack 2.
If you can make sure before you launch game, when you right click your exe to run with your desired graphics processor (i.e. amd or nvidia).
Note: Disable all firewalls/antiviruses as well.