f you're trying to open a PowerPoint Show (.ppsx) attachment in Outlook and encounter an error like:

"The presentation cannot be opened. Your antivirus program may prevent you from opening the presentation..."

You're not alone. This issue often arises due to security restrictions from your antivirus software or Microsoft Office's built-in protection settings. Here's a complete guide to troubleshoot and fix this problem safely.

✅ Step-by-Step Solutions

? 1. Save the File Locally First

Instead of opening the file directly from Outlook:

• Right-click the attachment → Save As

• Save it to a secure location like Desktop or Documents

• Open it from there. This avoids issues caused by the temporary cache path (e.g., INetCache).

? 2. Disable Protected View (Temporarily)

Microsoft Office may block attachments from the internet or email. To bypass this (only for trusted files):

• Open PowerPoint

• Go to File → Options → Trust Center → Trust Center Settings

• Click Protected View

• Uncheck:

  • Enable Protected View for Internet files

  • Enable Protected View for unsafe locations

  • Enable Protected View for Outlook attachments

• Click OK and try opening the file again

⚠️ Re-enable Protected View after opening the trusted file for safety.

? 3. Check Your Antivirus Settings

Some antivirus programs may block Office files:

• Open your antivirus software (like Quick Heal, Norton, Avast, etc.)

• Look for quarantine or blocked programs

• If PowerPoint or the file path is blocked, allow or whitelist it

• Alternatively, disable the antivirus temporarily, open the file, and enable it again immediately

? 4. Use PowerPoint in Safe Mode

Launch PowerPoint in Safe Mode to bypass add-ins or restrictions:

• Press Windows + R

• Type: powerpnt /safe

• Open the saved file from File → Open

? 5. Clear Outlook's Temporary Cache

Corrupted cache can also block files:

• Press Windows + R, type:

  shell
  CopyEdit
  %localappdata%\Microsoft\Windows\INetCache
  

• Delete unnecessary files in this folder

• Restart Outlook and PowerPoint

? Final Tips

• Make sure your antivirus is up to date

• Trust attachments only from verified sources

• Avoid turning off antivirus unless you’re sure the file is safe

? Conclusion:

By following these simple steps, you can resolve the “presentation cannot be opened” error in Outlook and safely access your .ppsx files. Always exercise caution when handling email attachments to protect your system from potential threats.