"You are attempting to open a file type that is blocked by your registry policy setting" (or "attempting to save a file")
In PowerPoint 2007 or 2003 you try to open a PowerPoint file or to save a file in something other than the default format and see either:
You are attempting to open a file type that is blocked by your registry policy setting
You are attempting to save a file that is blocked by your registry policy setting
This may occur because an administrator has deliberately changed settings that prohibit opening/saving certain file types in PowerPoint, or because of a change made by Service Pack 3 (S3) for Office 2003 or Post-SP3 hotfixes.
First, if you have Office 2003 and have just noticed this change in behavior, it's probably because SP3 has been applied.
In that case see this:
The page talks about making changes to the Registry. This can be complicated and may cause other problems on your computer if you make mistakes. But scroll down and you'll find files "to re-enable" the disabled formats. You can download them from Microsoft's Download Center and run them to fix the problem.
If you have Office 2007 or have 2003 but haven't applied SP3, try this page instead:
In any case you cannot do the following in PowerPoint 2007:
- Save a presentation in the PowerPoint 95 or earlier file formats
- Open files saved in PowerPoint 95 or earlier PowerPoint formats