Using single Tv as a monitor
 

Hi any help will be greatly appreciated, I have the usb 2.0 to hdmi adapter it works great untill I restart my pc, it will not read the usb. to get it to work I have to plug in my pc monitor in the the vga and then both work, but I would only like to use one monitor, is there a way to get the pc to read the usb to hdmi as my primary and only monitor?