Rikster, it was either an upgrade (keeping your Vista settings and files) or a clean install (wiping it out and starting from scratch). You are able to do both from the install DVD, it depends on what you choose at the install menu.
Do you want to keep the files you had in Vista? If not, I suggest you just start over and do a clean install:
http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html
Beware, this means you will erase all and any data which was on the disk before. It should keep a copy of most of it in a folder called windows.old.
If so, pleae give us more details about your system configuration. There will be some quesitons you will be asked, I suggest you check this post for the things needed to know to be able to help:
http://www.sevenforums.com/installation-setup/28129-questions-use-help-installation-issues.html
Tks