What kind of video clips and music are you having problems with? If the video is for example Divx (like most of the movies with .avi extension) you probably need codecs and maybe a different player (I don't like WMP much). Try in the tools section of www.vcdhelp.com, they have lots of codecs and players (many of them are freeware). If you don't know what kind of video files you have, download from there a little program called GSpot that will find it out for you.
Is the audio mp3? If so, you can try with winamp (www.winamp.com)
Have Toshiba S320 notebook WiFi with XP Home. Having trouble watching video clips and playing music. Should I download Media Player 10. Haven't really setup anything as far as Media goes if this matters or not. Error message says I should connect to the internet or insert media? I'm connected to the internet? Thanks