How to override GPU? It won't let me

I’m trying to click on override GPU on windows but it doesn’t let me, my curser just turn into a cirl]cle with a line through it meaning I can’t override it. Help please?

Override Compatibility Detection can only be enabled/disabled if Salad is not running. Keep in mind, that if your GPU can run Salad normally, this option may decrease your earnings by a significant amount.

Thank’s I have AMD RADEON GPU which has 2GB of VRAM, I have Intel Core I7 and it still says I can’t run it, will try to override later today and will reply to you if somethiing doesn’t work.