It is generally accepted that Ubuntu is the recommended operating system for running a production installation of Odoo. There are several reasons why this is true:

• Ubuntu is the primary target platform: While Odoo is released for Windows and still well supported, the Ubuntu installation continues to be favored. The development team for Odoo works primarily with Ubuntu for bug fixes and platform releases. It can be expected that, for the most part, Odoo development will be optimized around Ubuntu, not Windows or Mac.
• Ubuntu is open source: Installing Odoo on any Windows operating system is going to require a license from Microsoft. While using Odoo on your Windows PC or Mac is a viable and perhaps desirable solution for testing and development, it is unlikely you will want to run Odoo on a Windows desktop system for any production environment. Why? Well, this requires Windows Server, which has much higher license costs than desktop editions. With an Ubuntu installation, you get an entirely open source and virtually cost-free solution.
• Ubuntu has additional scalability options: It is possible to configure a more scalable solution under Ubuntu than what you can currently configure under Microsoft Windows Server.
• Ubuntu has strong community support for Odoo: The fact is that a vast majority of the production installations of Odoo are running under Ubuntu. When you run into trouble or management issues with your Odoo installation, you may find it easier to get assistance if you are running an Ubuntu installation.