My mother and stepfather were married for 60 yrs,I'm the only child of my mothers,my mother passed April 08,my dad passed today 11-26-09,the original was her to him,him to her,after her death he changed same,but not to me,he has altzimers and had been on medication for it prior to my mothers death,my question is since hae has no children do I have any legal rights?

Nope. If everything was left to your step fther then its his to do with as he wants.

If he never adopted you at any point, no you have no legal relationship to him so his brothers or sisters, he nieces or others would be the ones to get his estate if he left no will.

If he left a will, it will go to who he left it for.