Well i got a problem it started when i installed a free online game Americas Army. Well it didn't worked so i went to the AA forums. There a moderator said dat i shoud uninstall DirectX with the DirectX Buster. OK i did it well it went good somehow (installed the 8.1 version of DirectX) but then i couldn't install DirectX 9.0c. Well i tried alot of thingz noting helped.
 
Windows Xp Proffesional with SP2