It is in the UCCNC/Screens/ folder, the Default2019.ssf file.
In the file there are regions for the different motion controllers. If your controller is UC300ETH-5LPT then find the //REGION UC300ETH_5LPT and the //ENDREGION UC300ETH_5LPT and the screenset for you motion controller is between that. You could even first delete all other Regions for simplicity of editing the file, so they will not confuse you.
And keep the Loadpictures and the Addtabs to the last to remove, because they influences other things, so remove those the last time only, I mean remove other things like buttons, textfields, labels, lists etc. first.
Your screen resolution makes me assume that you work on a laptop. Please, write me some details:
- the exact type/model of your laptop - the version of Win 7 (Home/pro etc.), 64/32 bit, language of Windows and regional settings - is it updated by Windows update
I try to make a test environment to get the same results as you.