Adjusting Volumes

Hello everyone! So I have an Asus ROG 20 gaming pc which can handle DAW programs. Im about to connect my 5" studio monitors to my audio interface which is a Focusrite Scarlett 2i2 USB 2.0. I wanted to know how I would adjust the volumes. Do I turn the destktop volume all the way up and the volume on the monitors halfway, or do I keep the desktop volume halfway and turn up the monitors all the way up. Need to know for when I do my mixing and mastering to get the better result.