Microsoft PowerPoint 2010 opening PPTX files as a Picture Icon

I've got a user on a Windows 7 (x86) laptop with Microsoft Office 2010 installed, alongside Microsoft Project 2007. Whenever he tries opening PPTX files, no actual content is displayed but instead, only what appears to be an icon representing a picture file right in the center of the screen.

I've verified that a test file he cannot open is bad/corrupt because it isn’t opens just fine on my PC (Win 7, Office 2010). Regular PPT files seem to open OK on his computer. It's just the PPTX files that won't open properly. The strange thing is, there is no error message.

I have included a screenshot of PowerPoint when it opens the file.

Here's what I've tried thus far, to no avail:
• Repaired the Microsoft Office Installation
• Uninstalled Office 2010, rebooted and Re-installed Office 2010
• Ran the SFC /SCANNOW command in Windows
• Ran CCleaner's Registry Cleaner to remove any erroneous entries that might be there
I've searched around online but haven't come up with anything good that worked. Any suggestions

When you right click an icon and choose Properties does Open With say "Microsoft OFFICE 2010"?
Is this the click to run version?

Yes, when I right-click and choose OPEN WITH, I do NOT see "Microsoft PowerPoint" in the list - instead, it says "Microsoft Office 2010". I forgot to mention in my original post that I already tried re-associating the PPTX files with POWRPNT.EXE but as soon as I made the selection, I was returned to the screen we see here in the attachment I've included.Attachment 75529

Confusingly "PowerPoint Office 2010" is actually Office Picture Manager (OIS.EXE) - Not Microsoft's cleverest decision!
You will need to change the file association. If this isn't the click to run version you should be able to right click a pptx > properties. In Open With click CHANGE and then the Browse Button to find POWERPNT.EXE which should be in ProgramFiles\MicrosoftOffice\14.0
Make sure Always use this program is ticked and OK. If that's what you did I don't know!
If you do have click to run my advice is switch to the "real msi" version. This should be a free option.
If that doesn't help, then look at the website support.office.com how can I recover the file Recovery task pane.
https://support.office.com/en-US/art...9-3454d4a78585
Also assuming that all these suggestions do not help, you can try to use free PPTX Repair Kit or any other that you know. Maybe this will help. http://www.pptx.repair/