The main reason is that the Aero Snap feature is too sensitive. Other possible causes include the monitors being arranged incorrectly in Display Settings, or trying to move a window that is maximized.
1. Disable Snap
Windows supports multiple monitors and includes several helpful features to make multitasking easier. One of these is called Snap. While Snap is useful for organizing windows on a single screen—helping you quickly resize and position them—it can be less helpful when using more than one monitor. With Snap enabled, when you drag a window to the left, right, or top edge of your screen, Windows automatically resizes the window. This automatic resizing can interfere with dragging windows between multiple monitors. There are two ways you can work around this:
If you want to keep Snap enabled, try moving the windows quickly and directly onto the other monitor.Or, if you prefer not to use Snap at all, you can disable it.
2. Re-arrange Monitors
If you used dual monitors before upgrading to Windows 10, sometimes the upgrade process causes Windows to “forget” the layout of your monitors. For example, it might swap the left and right screens, making it hard to drag windows in the direction you expect.
