Ok, if you are working with v1 there are a few more steps that need to be done to get the PowerCMS up and running on your server.
To start after you download the files you should open up the read me htm file and start at step 1. You will need to start out by loading the sql file into your db. Each step along the way has a link that will take you to a page that details how to perform the step.
Start here on step one where you load the MySQL db, when you are finished with that or if you have any questions on that part let me know.