Did you try adding this reg key? Reg add "HKEY_CURRENT_USER\Control Panel\Desktop" /v ScreenSaveActive /t REG_SZ /d 0 /f
You could also enable a Theme to set it for the user.
If the screen goes black it could be the power setting and I had to set this reg key to disable power settings.
The last attempt was trying:
I will try your suggestion