Did you try each of these steps:
Are you now booting the Vista Repair CD to attempt repair? The error you are getting is not one you would get if you successfully booted the CD to run Repair. Follow these steps to make sure you are booting CD: Clear CMOS - 3 Ways to Clear the CMOS - Reset BIOS
Look on first boot screen for key given to press to Run Recovery. If not there, look in your Manual which you can download at the manufacturer's Support Downloads webpage for your model computer to learn how to run Recovery, then press those keys to try it.
If Recovery will not run from boot, the next thing to attempt is to wipe the HD to remove any possible obstacles to a Windows 7 clean install.[