If you use Linux and Windows as me you will find this post useful. It is a procedure for reinstall Grub after Vista's installation.
Use a Live CD with a linux distribution, for example Kubuntu:
1. From console with root privileges digit ‘grub‘ (in Kubuntu ‘sudo grub‘)
2. After digit ‘find /boot/grub/stage1‘, this will show a message similar to "hd(2,4)"
3. Digit ‘root (hd2,4)‘ <- this is the previous value
4. Digit ‘setup (hd0)‘
5. Last ‘quit‘
Bye