|Try downloading and saving the file to your PC. Then navigate to the file, right click > Open with > Choose Program.|
Click "Select the program from a list" > Click OK
In that list, find Powerpoint. (If it's not there, click browse and find it that way)
Click it, and then click the checkbox underneath that says "Always use the selected program to open this kind of file"
Click OK. The file will open in powerpoint. Close that off then try opening a file from IE again.
It should work.
PEBMAC - The biggest cause of Computing problems.
Damn ID10T Errors.