I know little about RealPlayer. I believe it has similarities to WMP in that it's a reference player; ie: when you add a file to RP it records the location of that file but doesn't move the file. But if you later move the file, RP won't be able to find it. This happens when people add music to their such type player directly from LW's downld folder. Better way to go would be to move your music from the LW downld folder to a music folder elsewhere on the computer before adding it to RP so it's permanently there & RP or WMP will have no problems finding it.

Re: Volume; it depends I guess. Some players allow you to increase the volume or normalise the sound so it's as loud as it can safely be. You should see if RP has this ability. In that way, you won't need to worry about system sound level, etc.