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Just installed Windows 8 and downloaded the Catalyst version which ATI website recommended. However it says that it can't start! My main monitor is connected to my PC via a HDMI cable and the display is not full screen (there is a blank padding area around display). Usually I change overscan/underscan settings in CCC to reset it but since I have no access to it, I wanted to know if there is any way I can change it without CCC (through registry maybe?) Thanks.

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Here is an answer regarding how to do this WITH catalyst: superuser.com/questions/57239/… –  Alireza Noori Aug 6 '12 at 20:08
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5 Answers

up vote 19 down vote accepted

I've had extensive discussion about the overscan/underscan dilemma with AMD developers who work on the Catalyst drivers.

The basic idea is that AMD would rather underscan some people whose HDMI displays don't overscan, and create too small of a picture (blank spaces around the picture), rather than not underscan and cause people whose displays always overscan (with no setting to change it and incorrect EDID information) to have the desktop display too large. The argument is that if the desktop is too large, then the user can't see where the Catalyst icon is or the start menu, and they therefore can't navigate the UI in order to make the appropriate change. So they are sticking to their guns on underscanning by default on HDMI to ensure that nobody gets stuck with a desktop that's too big for their screen (with UI elements hanging "off the screen").

I don't agree with the policy, but that's the way it is. It also seems to be a fairly unique decision among graphics driver developers, as I can't reproduce the weirdness on a number of other non-AMD devices: Android tablets, Nvidia cards, and Intel on-chip graphics.

There is a way to directly tweak the underscan/overscan on Linux by modifying values in the "PCSDB" (Persistent Configuration Store Database). I don't know what the equivalent is on Windows, or if you can even read/write the settings without using Catalyst.

I can't personally test this solution, but it appears that it worked for people on fairly recent drivers, so give it a shot: go to Tom's Hardware or I'll just re-post it here:

I found a fix for the overscan issue  
Go to the following key in the registry:  
Create a new DWORD: 
"DigitalHDTVDefaultUnderscan" = dword 0x0000 
Note: there might be several {####....} , should be the one with most of the ATI settings. 
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Thank you VERY much. It worked with the first attempt. I'm so happy :X –  Alireza Noori Aug 7 '12 at 5:11
Great answer. I don't understand why this problem exists in the first place (why isn't a pixel a pixel?), but I think the blame rests with display manufacturers. Given that, and what you've said, I agree with AMD that underscanning by default is the best course of action. –  lordcheeto Dec 3 '12 at 20:55
This question is unrelated to how to do it with CCC, and indeed the OP provided a way to do it via CCC in the original post. –  ÃŁŁǫǛȉЖΦΤїҪ Feb 1 '13 at 15:17
The argument is that if the desktop is too large, then the user can't see where the Catalyst icon is or the start menu, and they therefore can't navigate the UI in order to make the appropriate change. And yet they insist on shoving an icon to run the CCC into the context-menu of the desktop as though it is something people use 20 times per day (not to mention the CCC being easily accessible from the Start menu and Control Panel even without seeing the taskbar). ◔_◔ –  Synetech Oct 18 '13 at 18:20
This pushed me in the correct direction. I added this new registry key in the \0000 and \0001 directories to no avail. I then skimmed through the existing keys and found one titled TVEnableOverscan. Setting this to 0 in \0000 fixed it for me. –  MetalFrog Mar 20 at 11:02
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For Linux, the fix is to enter this in the Terminal:

sudo aticonfig --set-pcs-val=MCIL,DigitalHDTVDefaultUnderscan,0

(posting this here to just need a single bookmark for all platforms)

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I had a similar problem, and wasn't able to install Catalyst Control Center...so also unable to adjust the underscan setting.

I was able to overcome it (more like mask the issue really) and adjust the Screen size setting on my Samsung TV that I have my PC connected to. By the sounds of it this exactly what AMD were trying to work around.

Now I can see the whole screen in 1080p, and luckily the TV is clever enough to have different screen size settings for each hdmi input.

Perhaps a similar approach might work for PC monitors?

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Why don't you use the selected answer's approach? –  Alireza Noori Jan 27 at 12:11
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This isn't directly for win8 but it worked in server 2012r2 so I assume it is at least parrotable in 8.1 or 8. Anyway I removed the default underscan? (image is smaller than display) by editing the BestViewOption_Hdmi binary key found at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\{B380344A-9336-4C46-A52D-F53C6EAD0696}\0000\DAL2_DATA__2_0\DisplayPath_5\Option

where the GUID you are looking for is which ever one has lots of keys in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video\

again {B380344A-9336-4C46-A52D-F53C6EAD0696} in the regkey string is a GUID that is unique for me don't expect to see the exact same one on your machine.

This is on Server 2012r2 using CCC 14.1beta

Anyway hope this helps someone.

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I have a Hp pavilion dv6 with ati hd 4650 with windows 8.1 update.

In windows 8 it worked fine to change the values but in windows 8.1 update windows keep restoring the values so that black border is constant.

I solved it by specifically add user “system” to the 0000 regkey and anly allow system to read the values, and applied these security settings down on all keys,subkeys.

And now it works fine in Windows 8.1 to.

Hopes it helps someone.

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