Vista bootloader is a little different, so it won't fix Vista bootloader, but it will boot the Vista partition. It should boot from USB if your PC is set to boot from USB, and it is plugged in when you are using the cd. I have never tried it with USB, so I'm not sure. It is only about 100MB last time I downloaded it. Try it out. Just burn it to CD the way you would burn a live CD. Plug in your USB drive, put in the CD, reboot, and see if it is listed as one of the bootable partitions.