Mate, i don't know how to fix this problem, many user with e6400/e6500/m4400 will be glad if this boot os x 10.10 for pc works, me to. Windows for me - no problem, os x - know this 5 days. Only os x 10.6 works on this Dell but is old and not work properly. I want to fix the problem but i do not know how and where to start