The manual explains how to properly install PowerPoint. Also, you need to change several registers after installing PowerPoint:
https://xibo.org.uk/manual/en/media_module_powerpoint.html
However, the registers:
“EditFlags” in [HKEY_CLASSES_ROOT\PowerPoint.Show.12]
“EditFlags” in [HKEY_CLASSES_ROOT\PowerPoint.Show.8]
“EditFlags” in [HKEY_CLASSES_ROOT\PowerPoint.SlideShow.8]
They already exist and are REG_BINARY types. And the statement tells you to create the REG_DWORD type. Should I delete current entries and create new ones?