hello sir, my laptop model no 15r N5110,my system generaly cpu usage showing 30% to 90% but no any files open, than i given  dell service center so that service person told HDD some error(0146) coming so we need to change so changed but problem not solved now again service person told processor some problem so next we need to change please help me i don"t know i am going currect way. next i what todo.