Huh. Well, That may be from change of memory. Apparently, my friend sent his xbox to microsoft for a free repair. he got the red rings. He had all 4 and didn't know why. His problem was never the console. It was his power cord. They sent it back as it was with a new power cord and it worked...mostly. It is slow loading things up.
I honestly think it is because he is using a new HDD cuz he lost his original one.