I was looking for the specifications of your system and some pages from HP* website only mention Intel® HD Graphics 5500 while others also mention AMD Radeon™ R7 M260X. I suggest checking in your own system, in Device Manager or DxDiag report (press Windows* key + R key, type “dxdiag”, press OK). It is very possible that your system will need to use customized drivers provided by HP* instead Intel generic drivers.
Besides that, we strongly recommend installing the driver for your monitor, so it will be detected with the correct model rather than “Generic PnP monitor”; and using a straight high quality video cable.
You may want to take a look here: Why cant I access Custom resolutions in latest HD driver? (The old driver could!)
Thanks Joe. Below is the screenshot of "dxdiag"=>"display". Does this give you more information?
I tried looking for drivers for my monitor. But since it's not a brand name, I couldn't find it. I also copied "CustomModeApp" from an EliteBook G1 to "Windows/system32" of my laptop. But the executable file ran with an error. Are there any other files I should copy together? Thank you.
And one more thing to make it clearer. I don't see "custom resolution" in my graphics control panel. And I also didn't find "CustomModeApp.exe" under "Windows\system32" as instructed by Graphics Drivers — Custom Resolutions & Modes.
Try installing the latest driver with the zip installation method. Otherwise, try contacting HP*