You may need the following....(everything listed is 100% free & virus free)
AC3 (most used sound codec)
http://www.free-codecs.com/download_...hp?d=2114&s=12
Xvid (most used video codec)
http://download.divxmovies.com/XviD-1.1.0-30122005.exe
Winrar (most used to extract collections in .rar/zip format)
http://www.rarsoft.com/rar/wrar361.exe
Bookmark this thread if you ever want to get into torrent files, & need a file checklist to play your video/audio.