To re-size a window means to keep that window in its current position whilst altering its width and/or height. This is done by dragging (moving) the edges or corners of a window into its new width and/or height location. Only a non-maximized (custom sixed) window can be re-sized.

As you approach the left or right edge of a window the mouse pointer changes into the Left/Right directional cursor (Fig 1.1) and as you approach the top or bottom edge of a window the mouse pointer changes into the Up/Down directional cursor (Fig 1.2). These indicate that the window can now be re-sized (shrunk or expanded). Likewise. As you approach one of the corners of a window the mouse pointer changes into the Diagonal directional cursor (Fig 1.3) to indicate that the window can be re-sized in any direction (up, down, left, right or diagonally).

Fig 1.1  Move the cursor Left or Right

Fig 1.2  Move the cursor Up or Down

Fig 1.3  Move the cursor in Any Direction

Moving the Up/Down cursor (Fig 1.2) either shrinks or expands the window's height, whereas moving the Left/Right cursor (Fig 1.1) either shrinks or expands the window's width. Moving the Diagonal cursor (Fig 1.3) in any direction (left, right, up, down or diagonally) either shrinks or expands the window's width and/or height, depending on how you move the cursor of course. To re-size (shrink/expand) a window just follow these 4 simple steps:

1. Move the mouse pointer towards one edge or one corner of the window until the mouse pointer changes into a directional cursor. At this stage keep the cursor's position steady, otherwise the cursor will change back into a mouse pointer.
   
   
2. With the cursor steady; Click the left mouse button and keep it held down (clicked) whilst you then slowly move the cursor (mouse pointer) either inwards (left and/or upwards) to shrink the window or outwards (right and/or downwards) to expand the window.
   
   
3. When you have the desired window size release the left mouse button.

Fig 1.4  Position the mouse pointer over a window's edge so that it changes into a directional cursor




Fig 1.5  Click and hold down the left mouse button and then move (drag) the cursor until the window is of a desired size




Fig 1.6  Release the left mouse button to apply the new window size

The above expanded the window's width and height for the example. However. In reality you might need to shrink two windows to equal size, side by side, so you can compare their contents. For example. You might have two text files open, side by side, so you can compare them and/or copy text from one file to the other. Or you might need to shrink a window so it is not taking up too much space on the desktop but at the same you can still see its contents. These are the normal scenarios.

Take this scenario. You have the Documents window (folder) open small. You then create sub-folders and files inside it, but cannot see the new sub-folders and files because the Documents window is not big enough to view all contents (sub-folders and files). In this case you would have two choices. Either re-size (expand) the Documents window or simply maximize it. Remember. Each time you maximize a window you can then restore it back to its original (smaller) size. This way you get the best of both worlds - You maximize so you can see all of the window's contents and then restore back to a smaller (uncluttered desktop) window. Shrinking, Expanding and/or Moving a window only can be tedious sometimes, but sometimes that is the only choice you have.

Fig 1.7  Click on a mazimized window's RESTORE button first in order to then re-size it

A window can only be re-sized when it is not maximized (not full size, but custom size) simply because when it is maximized it is using up the whole desktop area (minus the taskbar area) and therefore has no edges. The only way to resize the window is to minimize it first by clicking on its RESTORE button (above).

Microsoft product screen shot(s) reprinted with permission from Microsoft Corporation.  As stated here by the Microsoft Corporation.