Do your research buddy: http://www.zdnet.com/blog/microsoft/...ows-core/12975 There is a reason 7.8 cannot be 8. Edit: Also, according to some engineering buddies at Apple, iOS5 for 3gs was NOT the same as iOS5 for 4/4s...they had to serverly tweak it down due to nonmulticore support, almost different entirely...hardware support was not there...