Hmmm. Let's see. You don't know what a PAD file is, but you want to edit it?
For the most part, a PAD file is just a subset of XML that's used to describe products and product specifications. It's being pushed by asp-shareware.org.
As far as a PAD editor, try putting "PAD file editor" in a google search. There appears to be a bunch of them available, but I would stick to one that might be recommended by asp-shareware.org.
Browser: Firefox, Netscape, Sea Monkey, Internet Explorer, .....
Actually I require knowing PAD file to submit my script in a directory. They terminate form submission; instead ask PAD file URL to submit. Thank you very much.