Why Does an External Monitor Only Duplicate the Laptop Screen?
A user tries to connect a monitor to a laptop to have an additional screen for work, but both screens show the same content. Which of the following should the user do to resolve the issue?
Community Insight
Tests whether you can distinguish a display-mode configuration problem (Duplicate vs. Extend) from a hardware detection or window-management problem.
A laptop and an added monitor showing identical images means Windows is in Duplicate mode rather than Extend mode. This page confirms that setting the external display to Extended in Windows Display settings is the fix, and explains why hardware additions or Windows tiling do not address it.
Choosing to buy a docking station (B), assuming the monitor isn't connected properly — the monitor already works, so the issue is the display mode, not the cabling or port count.
Community Discussion (3 comments)
Comments & Corrections
No comments yet — spotted an error or have a note? Share it below.
Expert Analysis
Why the Answer Is Correct
Windows supports four projection modes: PC screen only, Duplicate, Extend, and Second screen only. Duplicate, the default when many laptops first detect an external display, mirrors the same image on both panels, which matches the symptom exactly. Opening Settings > System > Display (or pressing Win+P) and selecting "Extend" gives the second monitor its own desktop area so windows can be dragged across both screens, which is what the user wants for additional workspace. No new hardware or driver installation is required because Windows already enumerated the monitor and is actively drawing to it. As one commenter put it, "Duplicate" = same picture. Extend = second workspace.
Why the Other Options Are Wrong
Option A is unnecessary because the monitor is already recognized — if the OS were not detecting it, the second screen would be dark, not mirrored. Option B adds cost and complexity without changing the output mode; a dock only provides extra ports, and the connection already works. Option C confuses window management with display configuration: the Windows tiling/snap feature arranges application windows on a single desktop and has no effect on how outputs are mapped to physical monitors. Only option D changes the relationship between the two outputs.
Community Comment Notes
Consensus among learners is unanimous for D, with one commenter summarizing the distinction between the two projection modes using the bear emoji framing of "Duplicate" versus "Extend". Another commenter, 351199f, notes that Display settings "allow you to configure how displays work on Windows, allowing displays to be extended, not just duplicated," which is precisely the configuration point being tested. ishan94 simply states that D is the correct answer. No commenter argued for a dock or the Add New Hardware wizard, reinforcing that this is a display-mode question rather than a connectivity one.
Official Reference
Exam Strategy
When a scenario says both screens show the same thing, the display is already working — so eliminate any answer that adds hardware, drivers, or window-management features. Look for the option that changes the projection mode (Extend) in Display settings.
Frequently Asked Questions
Why won't a docking station fix a monitor that duplicates the laptop screen?
A dock only adds ports and charging; the monitor is already detected and displaying an image, so the duplicate output is a display-mode setting, not a connectivity limitation.
What is the difference between Duplicate and Extend in Windows Display settings?
Duplicate mirrors the same image on both screens, while Extend creates a separate desktop area on the second monitor so windows can be moved between them.
Related Analysis
Practice All 220-1201 Questions
Access 105 questions with complete answers and detailed explanations.
View Full 220-1201 Practice Test →