• I have a Windows 10 Lenovo T440 laptop, which I have connected to a TV using a display Port to HDMI connection.
  • The TV is a Samsung 55" 1080P LCD TV.

Now, as soon I connect the devices and extend the display from my laptop to the TV, it drops the resolution of the TV to 640 * 400 and does not give me any option to upgrade the resolution. How can I solve this problem?

  • Did you disable the built-in monitor from Windows? – Julie Pelletier Jun 5 '16 at 2:14
  • No. Do I need to do that? if yes how? – Lost Jun 5 '16 at 2:23
  • Well I tried TV as the only monitor and that also does not seem to provide more options for resolution – Lost Jun 5 '16 at 2:54

The resolution provided by a graphics adapter is the sum of the total resolution of all the displays used.

You can change those settings by going on the Start button (bottom-left of the screen), Control Panel, Appearance and Personalization, Personalization, and then Display Settings. You then go to the Monitor tab from which you can select the different displays and the resolution to use on them.

  • I tried that. When i tried that on TV, it only shows upto 640 X 480 as only option – Lost Jun 5 '16 at 2:53
  • So you disabled the other display and the maximum output on the TV setting is 640 X 480? – Julie Pelletier Jun 5 '16 at 4:36
  • Are you actually using a direct HDMI cable? Now I'm wondering if you're using some cheap VGA to HDMI adapter. – Julie Pelletier Jun 5 '16 at 4:38
  • I am using Thunderbolt to HDMI adapter. No VGA involved – Lost Jun 5 '16 at 16:47
  • What's the model? I'm very curious, especially considering I thought this was only for Macs. – Julie Pelletier Jun 6 '16 at 4:20

You won't get much more more than 640 x 480 with VGA output.


Check if your PC Video Output looks like this : https://en.wikipedia.org/wiki/VGA_connector

Did you try updating your video drivers ?


  • You may be confusing the name used for a specific display resolution with the capabilities of the graphics card. A very common resolution limit for VGA output is 2048x1536. – fixer1234 Jun 5 '16 at 6:38
  • Right, VGA connector but resolutions like QXGA. Checked on fourmilab.ch/documents/howmanydots What would you say the SD resolution comes from then ? – Mantisse Jun 5 '16 at 6:46
  • Names have been assigned to certain common display resolutions based on their "multiple" of the original VGA resolution. However, that's unrelated to what the graphics card can output through the VGA connector. The quality of the Digital/Analog Converter on the graphics card determines how high a resolution can be outputted with good quality. Even on inexpensive cards, the manufacturers typically rate them as capable of up to 2048x1536 without noticeable degradation. The 640x480 doesn't really come into play as any kind of limit on VGA output. – fixer1234 Jun 5 '16 at 7:04
  • Ok, I did not know all that about what is still said to be VGA. – Mantisse Jun 5 '16 at 7:16
  • Actually it is MDP(Mini Dislplay Port) not VGA – Lost Jun 5 '16 at 16:46

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