If you just want to change the icon for a shortcut to the PPS file,
right-click the icon and choose Properties. Depending upon your version of
Windows, you'll find a Change Icon button somewhere.
If you want to change the actual icon associated with all PPS files on your
system, here's how to do it in Windows XP:
1. Open My Computer and choose Tools | Folder Options.
2. Click the File Types to and locate PPS in the Registered File Types.
3. With the PPS file type selected, click the Advanced button.
4. In the resultant Edit File Type dialog box, click the Change Icon button.
5. Browse to where you have saved your custom icon.
This will change the PPS icon only on your system and not in any other
system where you distribute your PPS.