I have two all-in-one PCs - an Acer Aspire and an HP Pavilion. I want to use my Acer as a second monitor as opposed to a computer. I have connected them via HDMI cables then pushed the "HDMI IN" button on the HP. However, while it spans the mouse across both screens, it's running from the Acer instead of the HP. Is there a way to change this so that it runs from the HP? There is no display option to run multiple screens unless you search for wireless ones which bring up no results - yet this option is on the Acer.