you now need to grab the image of that "mbr" heh heh which is sitting in the root partition of linux and give vista bootloader a chainload like command.
sorry I do not have vista to prove if this way works but
and you will be doing something like.....from within linux LIVE cd with a mounted usb stick....assuming its seen as /media/disk change to whatever
dd if=/dev/sda3 of=/media/disk/linux.bin bs=512 count=1
then after checking the size of linux.bin is 512 bytes on usb stick....boot into windows and follow steps from (4)