I am running Powerpoint 2007 and have a bunch of Powerpoint files saved in the 97-2003 Powerpoint format. I used to be able to open the presentations Powerpoint files in Powerpoint 2007 but whenever I try and do it now, I get the message: "Powerpoint can't read [filename.ppt]" If I click the "Show Help" button, it reads: "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." I would really appreciate some help here. I don't know why the Powerpoint files worked in Powerpoint 2007 in the past, but can't be opened in it now. I have uninstalled Office 2007, and reinstalled it, but still get the same problem. It happens also when I turn off AVG, Spybot S&D, SUPER Anti-Spyware and Malwarebytes' AntiMalware. Thanks.