Windows media player 11

[2756wm]

I cant watch any video that I dwnld in windows media player ver 11. I have tried to update wmp to resolve this issue with no avail. I used to use vlc media player but then my burning software would not burn it, as the media was formatted to vlc please help I am using windows xp with service pack 3 on an older pc with pentium 3 730mhz processor and 512 mb of ram my hard drive is 320g with a 20g slave, using a radeon 7000 series vid card and a soundblaster audigy sound card using lw version 4.18.8 with java version 1.6.0_10 please help