MAC INSTALLATION GUIDE CAN BE FOUND HERE:
GETTING STARTED - Windows Download Installation
Omnisphere 2 is available as a download for registered users through the Spectrasonics Webstore/Techshop. Once you have downloaded Omnisphere 2 via the Download Manager, follow this set of instructions to install it on your Windows system.
Note: You need over 64GB of free space available on your hard drive in order to continue.
Omnisphere 2 Installation
Step 1: From your Downloads folder, open the “Omnisphere 2 Installation" folder and then the folder called "Windows."
Step 2: Double-click the file "Omnisphere 2 Downloadable Installer.exe.”
Step 3: Click "Next" to begin the Omnisphere 2 installation process.
Step 4: Follow the steps as you're guided through the installation process.
Step 5: Make sure to review the Installation Info and Licensing FAQs and accept the license agreement.
Step 6: At the “Select Components” step you'll choose to install the 32bit and/or 64bit versions of Omnisphere. If you are uncertain which one to choose, select them both. The following steps will show you the default location for both versions of the VST.
Step 7: The default location of the large Omnisphere data files will be displayed next. If you wish to install the core library to a secondary drive, click the "Browse" button to choose a different location.
Step 8: Once the installation paths have been confirmed, the installation will begin.
Step 9: After the installation is complete, select "Finish.” Now it's time to open Omnisphere 2 in your host and authorize it.