Hi,
It sounds to me that you:
1) have downloaded the MSI file properly
2) double clicked it to install
When it's installed, you need to use the *START MENU* to access the Menu Designer OR make a shortcut to \Program Files (x86)\EasyUO_MD\EasyUO_MD.exe. It sounds like you're clicking the file that you've downloaded (the msi), instead of the shortcut/file that has installed on your machine after installation.
Do you have 'show file extensions' enabled in Windows Explorer? That will show whether you're clicking an MSI file or EasyUO_MD.exe.
Related but unrelated, I actually have this running successfully in Win10. Curiously it seems to work even if I don't run the programs as administrator, but I don't want to muddy the waters. Since EUO1.4 doesn't need to interact with client.exe, that seems to remove the 'run as admin' requirement (for me anyway).
EE