Navigate to the Ozone 4 download page on the iZotope website. iZotope offers a free, unlimited 10-day trial version of Ozone; even if you plan to purchase the full version, you must download this trial version first. Enter your email address and click "Proceed to Download." Fill out the registration information and click the "Proceed to Download" button.
Click the "Download Ozone 4.03b for Windows" link to download the Ozone installer. Save the file to your hard drive. Double-click the downloaded installer to run it.
Click "Next" at each prompt to move through the installer. When prompted for an installation location for the VST version, specify your VST plugins directory, which is usually either "C:\Program Files\VSTPlugins" or "C:\Program Files\Steinberg\VSTPlugins." Click "Finish" to complete the installation.
Purchase an authorization code for Ozone if you want to use the program past the 10-day trial period. Navigate to the Ozone page in the iZotope store and fill out your personal information. Click "Next." Fill out your credit card information and click "Submit." iZotope emails you a serial number for Ozone.
Double-click the Ableton desktop icon. Press "Ctrl" and "O" simultaneously. Navigate to the set in which you want to use Ozone and double-click it.
Click the "Plug-in" icon on the left-hand side of the Ableton Live window to open the plug-in browser. Scroll through the list of plug-in devices until you reach "iZotope Ozone 4." Drag and drop the device onto the "Master" track.
Click on the Master track to open Ozone. Click "Demo" to run the demo version of Ozone. If you've purchased the unlimited version, click "Authorize" and enter your name, email address and the serial number you received in the authorization email. Click "Authorize"; Ozone connects to the iZotope website and authorizes your copy. Click "Finish."
Select a preset from the Preset Manager window and click "OK." Ozone now applies its mastering effects to the master channel of the Ableton set.