Only download BMWizard from a trusted source to ensure integrity of both the software and your computer. This can be verified by the blue UAC window, as seen below.
Alternatively, you may always use the Automatic Updater included, if you have previously downloaded BMWizard before.
Just click on "Check for updates" within the Automatic Updater.
Download, and start BMWizard. Wither through the desktop shortcut, or through the start menu.
The next step is to connect to your car by connecting your cable to your OBD port and computer/laptop. Select your car model then click connect.
You can now use BMWizard for diagnostics, for coding, or for retrofitting whatever you want.