To program windows of any type to open to a size you want maintained, you need to drag them to that size using your mouse to left-click-drag and then click the middle Maximize button a few times from the top right of window.
However you cannot let the window touch any edge of the screen or it will react with a "Aero snap" effect which means you'll need to close the window and start over.
I discovered this after years of not being able to get Windows 7 to program windows to open exactly where I want them, which is almost always full screen. But because I was trying to drag them full screen, I was touching the edges of the screen when I dragged them which always spoils the operation. Once I dragged them as close to the edge as I could without touching it, the Aero Snap feature didn't spoil the programming any longer.
There is one more thing you must do though when you get the window dragged to where you want it. Go to the upper right middle button to Maximize and click it a few times. This programs the window to open to where you want it. If it goes back to where you want it every time you click it, then it has worked. If not close the window and start over.
