When using Powerpoint Viewer you might get errors trying to open a presentation file sent as attachment when using Outlook Express.
To fix it, use this tool
Using the PPSFix utility
Download PPSFix.zip (~12 KB). Unzip the file and run the utility. Select the file types that you want to fix, and then click Fix. Note that you need to login as administrator in order to use this utility.
Click Start, Run and type CONTROL FOLDERS
In the Folder Options applet that opens, select the File Types tab
Scroll down and locate the following entry:
PPS (Microsoft PowerPoint Slide Show)
Click the New button
Type Open in the the Action: text box
In the Application used to perform action: field, type the following exactly:
For PowerPoint Viewer 2003:
"C:\Program Files\Microsoft Office\PowerPoint Viewer\pptview.exe" "%1"
For PowerPoint Viewer 2007:
"C:\Program Files\Microsoft Office\Office12\pptview.exe" "%1"
Uncheck the Use DDE box
Click OK, OK
Close the Folder Options dialog
For PPT files
If the problem is seen for .PPT files, then make the above changes to the following file type:
PPT (Microsoft PowerPoint Presentation)