bought computer with messed up Ubuntu

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http://askubuntu.com – I recently got a dell inspiron B130 with an Ubuntu OS and the main users desktop is scattered allover the place , files everywhere but not in folders,how do i fix this? I am new working with this operating system ,used to windows versions. if i go into a guest profile the desktop is perfectly fine and everything works but i cannot make the system fix itself or dont really know where to start help??????? (HowTos)