Intel HD 4000 custom resolution???

I'm tyring to create a custom resolution on my PC for 1280x720. However after I create the resolution, I cannot find it anywhere in my list of resolutions, and I have no idea how to even apply the custom resolution. It's not showing up in either the Windows or the Intel graphics properties panel. Anyone have any ideas? I know this PC is capable of that resolution, because that's what I have Guild Wars 2 running at. Sometimes when I alt+tab out, my desktop sticks to 1280x720 and that's how I know my PC is capable of this.