Announcing the Updated VMware OS Optimization Tool

April 03, 2020

The updated VMware OS Optimization Tool is now available and introduces many new enhancements and optimizations that can dramatically improve the performance of your Horizon desktops and published applications.

Crafting a primary Windows image is an essential step in any virtual desktop or published application deployment. The OS Optimization Tool helps prepare and optimize Windows 10/8/7 and Windows Server 2019/2016/2012/2008 systems for use with VMware Horizon 7 and VMware Horizon Cloud.

For a step-by-step walkthrough of the complete process, see the Creating an Optimized Windows Image for a VMware Horizon Virtual Desktop guide. At a high level, this consists of the following steps:

VMware OS Optimization Tool flowchart Initial WM Creation, Windows Update, Apps and Agents, Optimize, Generalize Image, Finalize

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

  • Optimize
  • Generalize
  • Finalize

Why Optimize?

You may ask yourself, “Is it really necessary to optimize Windows, and what kind of benefits will it give?”

Windows is designed for a physical environment with dedicated hardware and can run lots of services and process that are not needed or necessary in a virtual environment. These all add to the load of the desktop, consuming unnecessary resources, reducing the performance of the desktop, reducing the consolation ratio, increasing login time, and generally adversely affecting the user experience.

The OS Optimization Tool can be used to easily disable or minimize the impact of these unnecessary services and features to improve performance and user experience.

Before Optimizing

As an example of benefits of optimizing, the chart below shows the CPU consumption for a standard installation of Windows 10 version 1809, where no optimizations have been applied. The chart starts from the user logging in and then leaving the desktop idle, with no attempt to interact or launch any application.

A few things can be noted from this:

  • The login process takes a considerable amount of time, and the CPU is busy for a long time.
  • The CPU becomes busy again after a relatively quiet time, when default scheduled tasks kick off.
  • The quiet period between login and these scheduled tasks is still consuming some CPU.

Chart showing the CPU consumption for a standard installation of Windows 10 version 1809, with no optimizations applied.

After Optimizing

In contrast, the chart below shows the same Windows 10 version 1809 desktop after being optimized with the VMware OS Optimization Tool.

  • Login is much quicker, and the CPU is busy for only 2 to 3 seconds.
  • The scheduled tasks have been disabled, and the impact from them is minimized.
  • The CPU quiets down to a low state quickly after logon.

Chart showing the CPU consumption for a standard installation of Windows 10 version 1809, after optimization is applied.


The OS Optimization Tool now includes a new option and button to help in running the system preparation tool (Sysprep) with a supplied unattend answer file. This generalizes the Windows image, removing computer-specific information so that the image can be safely cloned and deployed throughout the enterprise.

Generalize with the OS Optimization Tool

The interface allows for the editing of the unattend answer file, if necessary. When ready, running Generalize will run Sysprep with the out-of-box experience (OOBE) and Generalize options, using the unattend answer file.


The third task that the OS Optimization Tool can assist with is to automate the common clean-up tasks that are typically run just before using the prepared image. These include system clean-up tasks and clearing information that makes the image cleaner and ready for use with Horizon.

Finalize with the OS Optimization Tool


The VMware OS Optimization Tool is the essential tool to aid you in creating a primary VM. Review the recent changes and additions and download the latest version of the tool, the user guide and the step-by-step guide to creating a primary image now.

I would like to recognize the hard work that went into this and previous releases of the VMware OS Optimization Tool by Hilko Lantinga and Tianqi Chen.

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