simplified flow:
1. download OST
2. Create DB in MySQL.
3. Create user and grant permissions to DB you created.
4. Unzip archive (or only extract the "upload" folder).
5. Copy contents of "Upload" folder into desired location.
6. If you haven't, setup the site in IIS and point it to said location.
7. Point a web browser to localhost (or domain if you setup DNS) Run installer.