Here is how I install mine. I currently have about 10 sites running on OSSN. In the top of your html folder create a folder for your installation. I usually name mine according to what the site will focus on such as biz, crafts, otherside, etc. I create my data folder the same way naming it something related to the site such as bizdata, craftsdata, etc.

Upload your files into your installation folder. Make sure your file attributes are set properly. In some cases if your site operates with cpanel you need to create your database and set yourself as user with full priveledges. Surf to where you installed your files...example http://mysite.com/myossn. The installation page should appear. If you can't get around the rewrite problem you might try adding ?page=settings to the end of your URL.

Be sure to fill in all boxes. Your host will probably be "localhost" if you are on a server other than your own computer. The box for installation folder should be filled in as well as the box for your data folder. Make sure these are correct. You will probably have to edit your data folder name if you set it to something other than the default. Click in the box and fix the name to match what you have. When this page is completed you should continue to the page to enter the admin info. Continue on and follow the instructions on the page.