Windows 7 Snap
Using/Disabling the Window Snap Characteristic in Windows 7
Once Windows 7 was unveiled, it introduced a brand-new feature called Snap–which permits users to simply resize windows when they happen to be dragged to the sides of the screen. Depending on where the windowpane is dragged, it increases vertically, takes up the complete screen, or arranges by itself side-by-side with another wide open window.
If you locate this characteristic more annoying than useful, you can disable this in the “Ease of Access Center” in the Windows Control Panel. Mouse click on the “Change just how your mouse works” hyperlink, scroll down to the “Make it better to take care of windows” section, then examine the box labeled “Prevent windows from being instantly arranged when moved to the edge of the screen. ”