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Right click on the desktop background. Choose Display Settings.
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Display settings explanation (Windows 7)
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Taskbar settings for use with extended multiple monitors (Windows 10)
There are also some helpful settings related to your taskbar (the bar at the bottom of the screen). Unfortunately, these settings are for Windows 10 only, as Windows 7 will not extend the taskbar across multiple monitors.To access these settings, right click in an empty portion of the taskbar and choose Taskbar settings. Below is a graphic representing a common set of taskbar options for use with multiple monitors.
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