VMware Horizon Guest OS Optimization

Microsoft Windows is designed for physical hardware, specifically desktops, and for that hardware to be accessed by just one user at a time. A default installation of Microsoft Windows contains several configuration settings, components, and scheduled tasks that may not be required or are not desirable in a Horizon environment. Therefore, with virtual desktops, one-time system actions must be configured in the base image, and one-time user actions must be configured in the default user profile. Also, to reach a higher consolidation ratio, increasing the number of VMs hosted on a single VMware vSphere® host, VMware recommends turning off features that are not needed.

The VMware OS Optimization Tool helps prepare and optimize Windows 10 and Windows Server 2019, Server 2016 systems for use with VMware Horizon.

The optimization tool includes customizable templates to enable or disable Windows system services and features, per VMware recommendations and best practices, across multiple systems. Since most Windows system services are enabled by default, the optimization tool can easily disable unnecessary services and features to improve performance.

At a high level, building an optimized Windows image consists of the following steps.

The OS Optimization Tool helps with three key steps in this process:

• Optimize
• Generalize
• Finalize

Best Practices

To make the most of the OS Optimization Tool, follow these best practices:

• Take VM level snapshots before applying any changes so that you can easily revert to the previous state if needed.
• Use the OS Optimization Tool on a base image. Apply the tool to an unused system that has been built to match the configuration that you will deploy for virtual desktops or RDSH servers.
• Disable as many unnecessary Windows OS components as possible. Consider disabling everything and then performing user-acceptance testing (UAT) to see if there are problems. Re-enable any components that cause a problem when disabled.

Unblock Executable Files

With different versions of Windows 10, it has Windows security will prevent executables from running and present an “Open file – Security Warning.”

• Open the file properties of VMwareOSOptimizationTool.exe and check if there is an Unblock option. If there is, select it and apply it to ensure that this executable will be allowed to run.
• If you have also copied in SDelete64.exe and LGPO.exe , unblock these executables.

For a step by step walkthrough of the complete process, see the Creating an Optimized Windows Image for a VMware Horizon Virtual Desktop guide.