Why does comparing PPT 2010 files with different content yield no differences?

Question

I have a PowerPoint 2010 presentation with 523 slides in it. I sent a copy to a colleague, he modified a few slides (added text to them), and sent it back to me. When I use the PowerPoint comparison on my original file and on the file he sent back, nothing happens, where "nothing" means:

• After clicking "Merge" (from the Review>Compare dialog), I get the "working" hourglass cursor.
• After a while, I see a dialog box with "Press the ESC key to cancel merging the document" in it. After a few seconds, this dialog box disappears.
• The cursor returns to normal, and I can navigate around in my document, but there is no pane showing me the differences between the presentations.

I get the same behavior regardless of which of the two pptx files I open first.

Any idea how I can get the PowerPoint comparison feature to work? Or is there another way for me to find the edits my colleague made?

Answer 1

I'm afraid you're going to have to uninstall and reinstall Office, since a repair didn't get this feature working again.

Answer 2

I tried comparing two slightly-different versions of the 4MB PPT file (where fonts are not embedded). Same result--no review pane appears when the comparison completes. I then repaired MS Office, rebooted, and repeated the experiment. Same result: no comparison pane.

While running the last experiment, I kept Task Manager open and watched the memory usage meter. Memory use barely topped 6GB, and Available and Free memory never went below about 10GB and 7GB, respectively. (My machine has 16GB memory.) It seems unlikely that PPT is running out of memory. Even if that were the case, I'd expect PPT to issue a diagnostic of some kind rather than silently aborting the operation.

Answer 3

Thanks, since you tested using a large presentation, we haven't ruled out that this is a memory issue. If you try the same thing with a small presentation and it still happens, we know that your PowerPoint installation is malfunctioning. If it doesn't happen with a small presentation, then it's more likely that PowerPoint is running out of memory when faced with a big file.

If you get the same result with only a few slides, then first try repairing PowerPoint:

1. In Windows, click on the Start button, then on Control Panel.
2. Choose Programs, then Programs and Features.
3. Right-click on Microsoft Office 2010 and choose Change.
4. Select Repair, then click on Continue. Let the process complete and test on both a small and large presentation.

Answer 4

They are pptx files.

Per your suggestion, I took my original file, edited it to add one word to the comments below the first slide, saved it, and closed PPT. I then opened the original and did a comparison with the revised version. The behavior was the same as I described above: no revisions pane appeared.

The files in question are about 20MB each, because I've got the fonts fully embedded. I need to do that, because the files get used by different people in different offices with different font configurations, so the PPT files need to be completely self-contained. Without embedded fonts, the original file would be about 4MB in size.

Answer 5

That's not the normal operation, as you've guessed. The Revisions task pane should open at the side of the screen and you should be popped to the slide that has the first variance between the 2 files.

These are .pptx files, I hope, the feature doesn't work correctly with .ppt format.

523 slides is quite a few, what is the file size? Your description sounds like PowerPoint is giving up before it gets through the whole presentation. As a diagnostic, can you load a small presentation, make a change, save it with another name and compare it with the original? This will indicate whether the feature is working at all on your installation.