A couple of ways. Go to LW's Library window & select Saved Files folder & press Explore & this will open the folder up for you. Then double-click the video. Also within LW's Library window you can select the video & press Launch. You can move the video somewhere else & direct your video player to it. If you need xtra CODECs you can get them here: http://www.free-codecs.com/

Get yourself a backup video player just in case. VLC is free & has in-built codecs: http://www.videolan.org/vlc/ (choose nearest mirror site)