Managing separate windows that are open within Windows can be a real pain especially if you're trying to slot them together neatly.
Linux and Mac OS do this job well but with Windows, you'd be best to try something like AltDrag to help things fit together more neatly. AltDrag is a program that attaches to your taskbar and allow you to drag windows from point to point by holding down the Alt key.
In addition, if you press Shift-Alt alongside it, AltDrag joins the windows between them by the edge or hit the edge of the screen. It is a bit annoying that you have to use the keyboard at the same time as dragging and it would be easier if you could just activate it by default in Windows but it's better than nothing.
Simple and lightweight, AltDrag can greatly improve the way you drag and drop windows on your desktop.