1. First thing to try... create a new Google Slide deck and click "File">>"Import Files">>"Upload Files". Load in your Powerpoint/KeyNote presentation. Click through your slides and ensure they still look like you want them. Hopefully this works and you are done!
Oh no! My slide formatting got messed up when I tried importing into Google Slides! 2. Okay, no worries. Here's the next thing to do. Go into PowerPoint/KeyNote and save your slides as images (PNG, JPEG, etc.): In PowerPoint you do this by "File">>"Save as">> select jpeg format from the dropdown menu. In KeyNote you do this by "File">>"Export to">>"Images"Create a new Google Slides document and insert one picture per slide. If you have animations on your slides you will unfortunately have to go into PowerPoint/KeyNote and create one slide per animation step. You'll have a lot of slides but this is a fool-proof way to get your slides to show up properly.