The presentation cannot be opened. Your antivirus program may prevent you from opening the presentation. To fix this problem, ...

The presentation cannot be opened. Your antivirus program may prevent you from opening the presentation.  To fix this problem, make sure your antivirus program is current and working correctly.  If the problem persists and the presentation is from someone that you trust, turn off your antivirus program, and then try to open the presentation again.  If you do this, make sure you turn on your antivirus program again after you open the presentation.