PowerPoint can't open downloaded presentation files.

Hello,

I currently own a retail version of Office 365 Home Premium 32 bit.

Every time I try to open a .ppt or .pptx file downloaded from the internet I get the following error message:

"Sorry, PowerPoint can't read (FilePath)."

There's also a "Show Help" button on the message. If I click it, the following message shows up:

"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."

The presentations open fine in other versions of Office and on PowerPoint Viewer 2007. I already tried turning off my antivirus and firewall and I still couldn't open the file. I spent the whole day researching and found some other threads about the same error, however none of the solutions proposed worked for me - including doing a clean reboot, reinstalling Office and changing the location of internet explorer's temporary files.

Here are some of the threads I found - I did everything they said but nothing worked still:

http://answers.microsoft.com/en-us/office/forum/office\_2013\_release-powerpoint/powerpoint-2013-error-the-presentation-cannot-be/7625a247-d172-4a67-81db-1cabca405af8

http://social.technet.microsoft.com/Forums/en-US/officesetupdeployprevious/thread/f5b26fb0-8f76-4bd6-8db2-1f556dbd5fb4

I have a Windows 8 64 bit operating system.

Thanks,

Daniel Lima