MFED: To CPU/GPU usage: Unfortunately I have no programs to measure it playing Balde Runner at same time ...any suggestion?
I would suggest to run the game in Windowed Mode and check the CPU/GPU usage with Windows Task Manager.
MFED: Yes, I can try and run the latest version of ScummVM (is there a risk that might corrupt the GOG-config-file? Because I am not into the technics of ScummVM), but I ask for patience for an answer.
ScummVM will create another config file which, as far as I know, will reside in your User's Roaming data folder. The path for that would be sometihng like:
"C:\Users\username\AppData\Roaming\ScummVM\scummvm.ini"
or equivalently:
"%APPDATA%\ScummVM\scummvm.ini"
GOG uses a local ScummVM config file which resides in your Blade Runner game folder and it is called "project_nov.ini"
In order to start Blade Runner windowed, when launching it with via GOG shortcuts, you can edit that project_nov.ini file with a text editor and change the:
fullscreen=true
to
fullscreen=false
Switching between fullscreen and windowed mode should be possible at runtime with Alt+Enter.