To launch a file, you select it from the LimeWire (LW) Library window & press the Launch button. With nothing selected, nothing will be launched. To find your downloads, select the Saved Files folder & select files within. You can also access this folder easily by selecting it & pressing the Explore button & this will open the folder up for you.

For playing videos, we normally recommend VLC - (click on link) _ (choose nearest mirror site) because it is reliable & has in-built codecs which are mini program attachments the program uses to read & convert different formats to play them. Perhaps best if you make VLC your default player for videos (though it can also play most audio formats): Setting Default video app

If you wish to preview a file that is downloading, it needs to be at least 5% downloaded.

I have the same problem with listening to music. I know where my files are located though. When I try to launch them in LimeWire nothing happens so I will then go to the actual file itself and try to play it in my media player and it acts as though it is playing, but no sound comes out. My volume is turned on and up also, because I have no problem playing a mp3 that I downloaded the night before.