Saturday, February 2, 2013

Fix HDMI Overscan without Catalyst

If you hook up your screen using HDMI cable, you will often get annoying borders and distorted graphics due to so-called "overscan". This technology is used with screens that were produced somewhere around stone age and use CRT technology. CRT tube will cut off sides from the picture, effectively removing all or some of taskbar and start menu. Hence, to compensate for that, they artificially squeeze picture to make sure all of it fits. Usually, overscan will eat up to 15% of the screen.

Screens produced after stone age usually have LCD panels with exactly as many pixels as they can display, so the overscan technology is no longer needed. But for compatibility, manufacturers still support it and even make it default.

Micrtosoft supplies drivers for my ATI graphics card. I really do not want any other software. Only thing I must have which they don't let me configure is disable annoying overscan. I found this article, which didn't help me, but gave me an idea what to do:


  1. Go to regedit, navigate to HKLM\SYSTEM\CurrentControlSet\Control\Video.
  2. Locate a GUID with 0000, 0001, 0002 entries that has a bunch of values underneath
  3. Set following values:
    TVEnableOverscan: DWORD = 0
    DigitalHDTVDefaultUnderscan: DWORD = 0

Screenshot of my regedit
I didn't have DigitalHDTVDefaultUnderscan in that registry key, so I had to create it. Once I crated it and rebooted, screen which was connected to HDMI started working properly.

4 comments:

  1. Hi Sergey,

    I have the same issue and I'm hoping your fix will help, but I am uncomfortable changes values in the registry. In other words, I have no idea what I'm doing! When I double click TVEnableOverscan, I get a popup that allows me to change one value. Do I change that to 0? Also, do you need to change this in all three of those entries (0000, 0001, AND 0002)? Finally, how do I create DigitalHDTVdefaultunderscan?

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    Replies
    1. Josh, changing registry can severely cripple your system. If you are not familiar with registry editing and recovery, I would say it's risky for you to do this. Installing ATI drivers is better solution for you in this case.

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    2. I understand that it's risky, but I was planning to attempt the fix on an older system that I don't care about anyways. The issue is that my graphics chipset is no longer supported by ATI for windows 8, and therefore I cannot install CCC on my laptop. Attempting to install Windows 7 drivers that are provided by my laptops manufacturer (Samsung) results in Windows crashing during bootup. Every time I do it, I have to restore Windows to a previous state before the program was installed. If you could provide a more detailed explanation of how to do this fix, it would really mean a lot. That being said I understand that it could be time consuming to explain, and I understand if you're unable to do so at this time.

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  2. This really worked! Some time ago I could not find a way without using Catalyst. And I found this. So glad. I had to change values in 0000 only. Thank you so much Mr. Galtsev!

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