Download MobiUSviewer.exe from here. If prompted, you should Save the file as opposed to running it from the website.
Double click MobiUSviewer.exe from where you saved it and follow the instructions. Allow the installer to take all the actions that it needs to take, including the installation of drivers, if any. On some Windows systems, Windows User Access Control may popup a dialog asking whether the installer can access your computer – allow the installer access.
After the Installer finishes, you can open Mobisante files by either double clicking on them in Windows Explorer or following links to them in web browsers. Note that these are the only two ways you can open the MobiUS Viewer, i.e., you cannot open it via the start menu.
As a test of your installation, DemoImages is a zip file with a cinex and a bsx file in it that you can use, immediately. Simply open the zip file and double-click on the image you wish to view.