How can i get the Windows XP theme back?

Well, I'm using Windows XP, and I first had a changed theme (just original Windows XP, but silver etc. ) and now I can't get the Original Windows Theme back. I get this: Shell32.dll, desk.cpl and Control_Run.dll files are missing. I have no idea why? Does anyone knows how I can get it back to normal? Thanks.How can i get the Windows XP theme back?
Right click on desktop -%26gt; Properities -%26gt; Themes - Here you can choose theme... If no, then reinstall win xp - the easiest way :)How can i get the Windows XP theme back?
get it from any of the torrent web
Right click on desktop and select ';properties'; and then ';theme'; drop down list select windows xp';