Whether you're using an external monitor to work more comfortably on a laptop or you have two screens side-by-side for running applications simultaneously, Windows 7 and 8 include shortcuts to get your screens up and running in only a few button presses. Unlike older versions of Windows that required setup every time you plugged in or disconnected a monitor, 7 and 8 can switch between monitors with a tap of "Windows-P." After turning on your second screen, move windows to it by dragging or using the Windows Snap shortcut keys.
Press "Windows-P" to toggle how your computer makes use of two attached monitors, or of one laptop screen and one monitor. The "Duplicate" and "Extend" options leave both screens on. With "Duplicate," both screens show the same image. "Extend" gives you additional workspace for separate windows. The other two options disable one of the monitors. "PC Screen Only" ("Computer Only" on Windows 7) disables your second monitor, while "Second Screen Only" ("Projector Only") disables the first.
Drag any window off the right side of your first screen to move it onto the second. As a shortcut, double-tap the Windows Snap hotkeys: "Windows-Right Arrow" twice sends a window to the second monitor or "Windows-Left Arrow" twice to move a window back to the first monitor. Press "Shift-Windows-Right Arrow or Left Arrow" to move a window to the same spot on the other monitor.
Press "Alt-Tab" to switch between open windows on either monitor. While holding "Alt," press "Tab" repeatedly to select other programs from the list, or click one to pick it directly. You can also simply click on a window to activate it -- move your cursor off the right edge of the first screen to reach the second.
Press "Ctrl-Tab" or click a tab's title to switch between tabs in your Web browser. You can't split two tabs between two monitors -- to view a different website on each monitor, open a second window of your browser by "Shift"-clicking its link on the taskbar or double-clicking its desktop link again. If you use Firefox, you can split an existing tab into a separate window by right-clicking a tab and picking "Move to New Window."
Use the "Switch Windows" button on the View tab of Word or another Office application to switch between several open documents. Other View tab options such as "Arrange All" and "View Side by Side" lay out multiple windows for simultaneous viewing.