i can't hear anything
 

I've had limewire for ages and have had no problems with it. However now when it plays music files it gives no sound?

Has anyone else had this problem or any idea on what might have happened, have i changed one of the settings?

Turn the volume control up! lol No seriously, check your audio settings. If LW is the only app it happens to, then chances are you're using LW's media player. There's supposed to be improvements in the >W beta 4.1.8 & even more in the up & coming 4.2 (whenver that'll be.) But may I suggest that in the meantime you use your default audio player. Go to LW's menu Tools-Options & Player. Deselect LW's media player & your default p3 player should play instead. In the image below you'll see the media player's option box ticked. You need to UNTICK IT!!! (You'll need to Press Apply & OK & quit LW & reopen it for changes to take effect!)

Depending on the status and configuration of your comp (HD usage, CPU usage, RAM available, blah blah...) the LW player might take a while before it actually plays a song (or anything else for that matter) after you click Launch on a file. Sometimes it might even skip during playback (I'm hoping that this won't be that much of an issue in the latest version of LW as the player has been improved).
Anyway, try clicking a song file and waiting for awhile.
If nothing happens, try doubleclicking the file (not Launching it with the Launch button). Again, wait a while.