sure.
(i assume you're on Windows 98)
You need to go into "My Computer" and go onto your "C" drive. From there, select the view menu, and choose "folder options." Then, click on the "file types" tab, and find the php file type. Double click on it, and a new window will appear. Near the top of that window is a button labeled "Change Icon." Click on it.
If the image you downloaded is an icon file (.ico), you should be able to click "browse" and find it. If not, you'll need to use Photoshop or something to convert it to an ico.
Hope it works!
