The window snapping feature in Windows 10 has greatly been improved upon since Windows 7. Even back then, it was pretty awesome but with Windows 10 and the lessons Microsoft learned from Windows 8, the feature has been made all the better. Among the many other things that you can do when snapping windows, resizing two at the same time is a very useful new addition made in Windows 10. Here’s how it works.
Snap two windows side by side. Once you’ve snapped the two windows, and either one of the two is active move your cursor to the center where the two meet.
When your cursor is positioned over the edge of the two windows, a shadow bar will appear over it. Wait a split second if it doesn’t appear right away. The bar indicates that the resizing feature is active.
With the shadow bar visible, click and drag to resize either one of the Windows. If you drag to the right, the window snapped to the right of your screen will decrease in width and the one on the left will be given more screen space. If you drag it to the left, the window on the left will become smaller with more screen space going to the window on the right. When you’re dragging the cursor, a solid black bar will appear next to the window that is being resized. The other window will not be resized until you release the mouse button.
Once you release the mouse button, both windows will be resized. One will be larger than the other, obviously. You have to be running Windows 10 build version 1511 in order to use the feature since it isn’t there in older builds.