If you have winamp Or i would assume any mp3 player Go to the xolox partial Folder right click on one of the .xlx Files and hit open with and choose winamp and click the Always open with this program. Thats how i use it too play mp3's i'm downloading ...and to check videos you can open in windows media player usually plays the videos before they are completed but sometimes for it to paly it it must be completely downloaded.

Windows media player will only sometimes play a partially downloaded file winamp has everytime... I guess its mostly trial and error hope this helps a bit