Question Question in BIOS, switchable graphics options, there’s no options but “muxless”, what to do? (PC NOT a laptop)

[moehamm]

I’ve had this problem that I couldn’t get any display from my dGPU so I hoped into the BIOS -> Advanced tab to change the Switchable Graphics settings, but no options was there but the "muxless".
I've read about it and understood that I can plug the dGPU into mobo, put the display on the iGPU and I’d get to use my dGPU.
Is there any setting in the bios to unlock more options in the Switchable Graphics menu?
it's from American Megatrends ARKTEK H61 for prebuilt OEMs.
*The dGPU works (Tested on another system)
* The PSU is 650w so it can power the dGPU so it isn't a power issue.

https://imgur.com/a/E9mCD8D

View: https://imgur.com/gallery/E9mCD8D

 

[rgd1101]

full system spec? include make and model of the psu

 

[moehamm]

full system spec? include make and model of the psu

it's an old lenovo system that i'm trying to get it back to life
i3-3240t 3.4 GHz
x2 4GB 1600 DDR3 Crucial RAM
GTX 460 OC 1GB version
EVGA 650W PSU
H61 mobo Arktek
1TB WD HDD