Problem with Diablo 2 : Lord of Destruction ? ? ? ?

Weell .. i am trying to download Diablo 2 : Lord of Destruction on my computer . My computer currently is Windows XP . I downloaded Diablo 2 alright . But when i put in the Expansion Disc , it said ' Play Diablo 2 : Lord of Destruction ' . I was like okay , and clicked on it . ( it didn't even let me have a chance to download it X.x ) and a pop up said ' Please Insert Diabloo 2 : Play Disc . ' So I inserrted the Play Disc .. and it took me back to the original Diablo 2 .. and the one time it told me to ' Insert Expansion Disc ' i inserteed it and was going on battle.net and it was working fine but before i got to log in it said ' Battle.net can not identify the application version ' or something llike that !! ?? any ideas would be appreciateed . thnx DMG * (: