Don't do this with PowerPoint. Seriously.
In Do this before you use PowerPoint for anything serious we show you a few things you should always do before you start using PowerPoint in earnest.
There are also a few things you shouldn't do in PowerPoint unless you really, really know what you're doing and why. And even then, maybe don't do it.
Don't bounce presentations between different versions
Between different Windows versions, between Windows and Mac versions, or saints preserve us, between PowerPoint and Google Slides or other non-PowerPoint software substances. All manner of things break when you do this.
If you're collaborating with others, move "preview" versions of the presentation back and forth as needed, but confine the "real" editing to one file in one or the other of the versions, not both.
Don't copy and paste pictures and other content from the internet into PowerPoint
Or at least be cautious about it. Sometimes copy/pasting (or drag/dropping) pictures from browser into PowerPoint can create mysterious links to the original file on the internet. When in doubt, right-click the picture in your browser, choose Save Picture As and save it to your hard drive. Then use Insert | Pictures | This Deviceto bring the picture in.
Don't link images
When you insert pictures as described above, you may notice an option to Link to the file. Unless you have a good reason for doing it, don't. PowerPoint's image links break very easily. It's generally safer and more effective to embed the files (in other words, insert them normally, not linked). Or if you want the images in your slides to update when you change the original image files, choose Insert and Link. That way, if the link breaks, your picture will still be there.