You could try downloading EasyBCD from neosmart technologies to repair the vista bootloader. The instructions I have found to repair vista bootloader are below:
To FIX VISTA MBR: Boot up from Vista Installation DVD and select Repair Your Computer option (its below Install Icon). Select Windows Vista -- Command Prompt.
Execute this at command prompt:
EasyBCD Download Page:
I've never used vista so obviously haven't tried this.