i cant play any music video clips on the net

when i try to launch my yahoo radio that works ok but what annoys me is that
i cannot listen or hear any launch videos, it just says that it is
configuring, my media player, in fact i cant hear or see any media clips on
the net, i have number 9 windows media player, and have 7 and half gigs left.
and have 128 m.b. i have the latest direct x 9.oc, and have macromedia flash
player and java sun microsystem.
also when i try to play my music in my puter by clicking on start,
documents,and settings,,my music , without clicking on media player without
the cd, it wont play anymore, so it is probably somthing i have ckicked on or
off, but it is really frustrating me, everthing seems to be working ok with
other programs, but there is just that internet clips, and slides wont play