Win XP Profile reset

[RobFDB]

My boss came to me this morning about a strange problem on his home PC that's left me stumped. Last night he turned it on and logged into windows like he normally does. Upon logging in he noticed that the background had changed back to the green hills desktop and the theme back to the standard windows xp theme. Then when he ran Outlook it ran the new user wizard and all his emails had disapeared. However all of his files and pictures in my documents were still there. Can XP do an automatic, partial system restore? Anyone got any ideas? I'm stumped cause i use 2000 Pro.