Hello Fiery, welcome to Seven Forums!
Here is one of the better options, you can have a Windows 7 clean install and the Vista too.
Have a thorough look at this tutorial at the link below to see a way to create a partition ahead of the current Vista partition, so it will be extremely easy to move your data from Vista to the new Windows 7 partition and when the time comes to remove Vista this method makes that so much easier.
Be sure to post back with any questions you may have and to keep us updated. Dual Boot : Create Partitions Using PWBD