First thing would be to fire up the Win7 installer, delete the Vista partition, and use it for Win7. When you install, it will set the Win7 partition active, so you'll have to probably set OSX active again to get your bootloader working properly (I don't know what you're using, but this is usually the case with Chameleon). Do the same thing for Fedora - delete the partition and install UNR in its place. Just be sure to install GRUB to the Linux root partition - NOT the MBR or "sda".
Worst case, you'd have to set OSX active and also reinstall Chameleon to the MBR. Should be simple if you have a Chameleon bootloader on USB somewhere, or they're easy to build yourself. If you have a Mac somewhere, it's as easy as installing Chameleon to a blank USB stick and booting with that.