These are the bullet points from here
HERE
1.There is a quick fix
HERE that will probably work with 2007
or
2.Right click on the file and select "Open With" from the pop-up menu
Select "Choose Program"Locate the program(.exe file) you want Windows to use
to open files of this type and select it
Put a checkmark next to "Always use the selected program to open this kind of file".
Click OK
or
3.Edit the Open action for the file association directly
(file names may vary) -
Use Windows Explorer to locate a PowerPoint PPT file.
From the menu bar, choose Tools, Folder Options
In the Options dialog box, click the File Types tab
Scroll through the Registered File Types list to Microsoft PowerPoint Presentation and double-click it.
In the resulting Edit File Type dialog box, double-click Open in the Actions list.
In the text box labeled Application used to perform action, you should see
"X:\abc\def\PowerPnt.EXE" "%1" or similar
where X:\abc\def\ represents the full path to the folder where PowerPnt.EXE is located. If you don't know the exact path, use the Browse button and locate PowerPnt.EXE.
The quote marks should be entered exactly as shown.
One set of quotes around the path to PowerPnt.EXE, another set around "%1"
Click OK and/or Close until you're back in Windows Explorer.
Now try doubleclicking the problem PowerPoint file again.
