1Fixed: Media Center PC wakes in wrong resolution

Since I upgraded my HTPC to an AMD A5400 series (from the old E350) I have had a prob­lem where on wake from sleep the res­ol­u­tion would be set wrong (1024×768 I think) instead of the full 1920×1080 that the TV sup­ports. Exit­ing media cen­ter would trig­ger a res­ol­u­tion cor­rec­tion and then media cen­ter could be reloaded without issue. This was not sat­is­fact­ory as a solu­tion.

After sig­ni­fic­ant search­ing (google res­ults just aren’t as good as they used to be), I even­tu­ally found some vague inform­a­tion sug­gest­ing a registry solu­tion. Some more search­ing on some of the registry key names turned up a dis­cus­sion on Microsoft Com­munity. As best as I can tell the issue is due to a com­mu­nic­a­tions break-down between the TV, the graph­ics card and Win­dows. My old sys­tem had used DVI, the new sys­tem uses HDMI. This was appar­ently the trig­ger for the prob­lem. I didn’t want to go back to DVI, and con­sidered this a “work around” rather than a fix any­way, so I decided to exper­i­ment with the registry solu­tion.

The place to work on is HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration
In this key are a set of sub­keys with long cryptic names. I believe each refers to a mon­it­or, screen, or remote desktop screen. Each con­tains a set of res­ol­u­tions and col­our depths amongst oth­er things
Each cryptic­ally named key con­tains a sub­key called 00. This itself may include 2 sub­keys called 00 and 01.
In the par­ent 00 key are 2 val­ues of interest — PrimSurfSize.cx and PrimSurfSize.cy
Inside the child 00 and 01 keys are val­ues called ActiveSize.cx and ActiveSize.cy.
Chan­ging the val­ues of these, to match the resol­tion you want, is the solu­tion.
There are 2 things to be aware of. Firstly — make sure you set the value as decim­al and let it con­vert to hex. Second — you need to find the right cryptic­ally named par­ent key for your primary mon­it­or. If you’re lucky you wont have many of these to look through before you loc­ate the one with res­ol­u­tion set too low.

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I had a sim­il­ar prob­lem. When I was reformat­ting and build­ing my Medi­a­Cen­ter, i was using a 1024×768 vga mon­it­or. Once I fin­ished, I moved it to my 1080p HDMI TV. If my TV was on before I woke up Medi­a­Cen­ter, everything was fine. If I turned on my TV after resum­ing the Medi­a­Cen­ter, the aspect ratio was 4:3. All I had to do to fix my prob­lem it was to run the Medi­a­Cen­ter TV setup again so that Medi­a­Cen­ter would lock the dis­play res­ol­u­tion at 1080p. Hope this helps you or oth­ers.