If you’ve downloaded .ppsx format presentation file then it’ll not from powerpoint 2003. This format is strictly for powerpoint 2007. But you can open it with powerpoint 2003. There is support compatibility pack available for powerpoint 2003. You can download and you’ll able to view .ppsx and other office 2007 file formats.
First download the compatibility pack from the link given here.
After downloading and installing this pack. You’ve to save .ppsx files with extension .ppt. Now you can open them with powerpoint 2003. Note: You’ve to install most of the high priority windows support update packs for it to work.
