windows media player going wrong again

Ok,I've just reformatted my pc and it had a few things
going wrong,My own fault i did download warez and not the
first time i had to do reformatted my pc cause of it{ps i
get top quality warez now so i'll be having no more
probelms.Anyway i'll get to the point,With windows media
player when every i try to use it with video it stops for
like a sec of less then carry's on.Happens with all
file's and all the way through the file in 4 to 8 bit
increments.Had this problem before but before it stoped
like after 1 half mounths it got alot worse.The picture
screen itself was violectly shaking up down left and
right,Making it inpossible to watch anything.

To help you out ill tell you little about my pc,It's a
1500mhz althon 256ddr Worst sound card you could imagine
and a geforce 4 4600ti running on windows xp.I have tried
everything to stop it,Like every option in windows media
player in all combanations.Also i should mention what i
still have this problem in all other music and video
devices i have like divx winamp and a mpeg2 decoder i
foget the name.

I really cant work out what the problem is,As i have all
the right spec hardware etc.Please help!!!!