In Windows Explorer (the file manager) are file extensions shown? If not, open explorer, click the File menu (upper left). Click Change Folder and Search Options, then click the VIEW tab. Scroll down to Hide File Extensions for Known File Types and UNcheck its box.
Now open Explorer to the Music folder and report what file extension is shown for the desired music file. If it's a typical one, as mentioned above, then Videopad should have no trouble loading it.
Open Videopad, click ADD FILES. Do exactly what you just did to find the Music file. Click on that file.
Music.mp4
