Video playback issues in PowerPoint are almost always one of two things: a missing codec, or a linked (not embedded) video file that's moved or been deleted. Here's how to tell which and fix it.
1. Check if the video is linked or embedded
Click the video, go to Playback tab, and check Video Format > Compress Media options — if they're greyed out, the video is likely linked rather than embedded. Linked videos reference an external file path, and if that file moved, was renamed, or the presentation was moved to a different computer, the video breaks.
2. Re-embed the video
If the video is linked, the fix is to re-insert it as an embedded file: delete the broken video placeholder, then go to Insert > Video > This Device and select the file again. This embeds it directly into the presentation so it travels with the file.
Tip: embedded video makes your file size larger but means it'll always play correctly on any computer. Linked video keeps the file small but is fragile — only use linking if you're certain the presentation and video file will always travel together.
3. Check the video format
PowerPoint plays MP4 (H.264) most reliably across Windows and Mac. Older formats like .wmv or .mov with unusual codecs can fail silently, especially on a different computer than the one the presentation was built on. If you're inserting a video, converting it to standard MP4 first avoids most playback issues entirely.
4. Update Office
Older versions of PowerPoint lack support for newer video codecs. Go to File > Account > Update Options > Update Now to check you're on the latest version.
5. Check for missing codecs (Windows)
If a video plays fine in your operating system's default media player but not in PowerPoint, a codec issue is unlikely — the problem is more likely the link/embed issue above. If it doesn't play anywhere, you may need the appropriate codec pack installed system-wide.
The bottom line
Before assuming the video file itself is broken, check whether it's linked or embedded — that's the cause in most cases, especially when a presentation worked fine on one computer and broke on another.