Harry travels back from the future just before the first Task in the triwizard tournament. Therefore the things develop differently. He takes up with Hermione and Ron with Marietta Edgecombe. Harry is the the Hair of Merlin and Hair to all four founders. In the end he saves Crouch and Snape and kills Voldemort by willingly giving his blood and forcibly take Pettigrews flesh. When Voldemort dies so to all the remaining Death Eaters. After that Harry opens his own school for magical education for all those too poor or to „unprivilidged“.
The story can be read at Schnoogle.
There is also a PDF.