Powerpoint Error Message

This is actually for Powerpoint 97, but it may apply in 2000. My user gets an I/O Error 6 when trying to open a blank ppt presentation through the software. All presentation icons look like greek. However, you can double click on the icons in thedrive where they are located, and the software opens it up fine. I uninstalled and reinstalled the problem to no avail. He's not printing...I/O error? Maybe something wrong with the HD? An error reading the disk?