Hi. Have you set your bios to boot from CD? If not it will look on your hard disc first which is your windows 7. To get into Bios press F2 on starting your computer(sometimes it may be the delete key.) When in Bios go to the settings for boot order and make the CD rom the first in the list. Put your recovery disc in and then start your computer. The files on the recovery disc will be read first and you should be able to reinstall Vista