I uninstalled from vista and from xp. I booted in xp and reinstalled it only there. Mac os x still doesn't boot. Nevermind. I guess I cannot have both vista and macosx. Thank you anyway. I told you a couple posts above that I had NST on both partitions. It wasn;t taht the problem. The mbr file in the NST dir does not boot mac os x. I see a blank sreen with a cursor like the darwin boot then the screen goes back to vista boot loader.