The browser can be installed for the current logged user account. This means that there is no way the browser is installed twice for the same user. If you suspect that this happened then the other installations are from the other users that are created on the operating system. To make it simple: one installation per user account. Also, I have tested the installation method and I can confirm that you can't install multiple Chrome browsers. Of course, if you use Chromium and Chrome then yes, it is possible but that's another story.
As Chrome has its own entry on the uninstall menu, then enter Add or Remove programs/Programs found in Control Panel and select the entry you want to install and click Remove and follow the instructions.
