Play all??

Win Xp comes with a new feature that in a folder containing music files there is link of "Play all" in the left list.
I used that option very effectively untill something happened to my PC & it stopped working.As far I can remember I did a repair install & might be after it this thing happend.
another thing which I`ve realised now is that,when I click on to play any song it dosn`t starts in the orignal Windows Media style which i uses(as it opens when i opens Win Media Player from my desktop.)rather it opens in a simple "Classic"like view.Hence I dont get my Win Media Player opens in the usual style as it opens when i get it opened from my desktop.

Now if anyone of u could help me in removing this problem.