like i make it to mac gui installation and i left it to eat when i came back it said that it can't make folder

i'm back at vista now

phenom 9950
hd4850
4gb of ram
m3a78-em

1 drive
partiotion 1 vista (want mac on this
2 backup ( i cant reformat has important files)

both of them are in sata and are achi what do i do