Change of render device, game won't start

[HKslan]

For reasons beyond me, my friend decided to change his Configuration > Render Device to see if it'd help the game run better on his PC. Now the game won't start and instead gives him this error.

He reinstalled, and I guess he forgot to delete his config file or something. What do I have to have him change in it?

Thanks.

 

[fiftyone]

Go look at "Error while starting game thread", just a little below this one.