Home ยป How to

Fix VMware Error Code 21001 in Windows 10

VMware is a virtual software that helps businesses to operate multiple applications and systems on a single server. VMware tools are essential in enabling features in VMware products for the management of operating systems. These tools need regular updates to work properly and to enhance the experience of operating systems. However, these updates sometimes lead to users coming across errors. One of these errors that are usually encountered is error code 21001. If you are also one of these users and are facing the same issue then we have a perfect guide for you. With multiple fixes, the guide will also take you through the reasons that cause this VMware tools upgrade fails with error 21001 issue. So, let us begin with this helpful guide right away.

Fix Error Code 21001 in Windows 10

How to Fix VMware Tools Upgrade Error Code 21001 in Windows 10

VMware tools enable features in VMware products that make the user experience better. This set of services helps in better management, improved guest operating systems, and seamless user interactions with OS. VMware tools help in passing the information from the host operating system to the guest operating system.

What Causes Unable to Install VMware Tools Error 21001?

Various reasons like the ones mentioned below have been seen to cause issues that lead to error 21001:

  • Weak internet connectivity
  • Unsupported operating system
  • Advanced isolation settings
  • Issues with Windows registry

There are a couple of methods that can help you with the error-free update of the VMware tools. You can try these methods on your system in the order they are mentioned below to fix Error code 1231 or 21001.

Method 1: Troubleshoot Internet Connectivity

The first thing to take into consideration is internet connectivity. While updating the VMware tools, it is important to ensure that you have a good internet connection. You can check the same using the steps that are given below.

1. Press the Windows key, type Command Prompt, then click on Run as administrator.

Open Command Prompt as Administrator. Fix VMware Tools Upgrade Error Code 21001 in Windows 10

2. Click on Yes on the User Account Control prompt.

3. Now, type the given command and press the Enter key to run the ping test.

ping www.google.com

 Type ping www.google.com and press enter key

4. If the ping is fluctuating, then try to run the network troubleshooter. Follow our guide to troubleshoot network connectivity problems on Windows 10.

Select the network adapter to diagnose and click on Next

If the ping response is above 150ms on your screen, then your internet connection is extremely slow and you need to either connect to a strong network or change the network to proceed with the installation of VMware tools and to resolve error code 21001.

Method 2: Verify Compatibility of Operating System

After checking internet connectivity, you must check if the operating system that you are using is compatible with the VMware tools and is not the reason for VMware tools upgrade fails with error 21001. The OS needs to be fully certified to avoid errors while updating the tools. Check the VMware Compatibility Guide to know more about the appropriate system needed for the tools to install.

VMware Compatibility Guide

Also Read: Fix Failed to Create a Proxy Device for the USB Device

Method 3: Reboot Guest Operating System

Another simple fix for the issue faced while installing VMware software tools is to reboot your guest operating system. It is possible that a simple reboot of the OS can help you with error 21002. Read our guide on 6 Ways to Reboot or Restart a Windows 10 Computer in case you are using a Windows guest operating system.

select Restart option from the drop down menu and hit Enter. Fix VMware Tools Upgrade Error Code 21001 in Windows 10

Method 4: Select Correct Operating System

The next method that is extremely helpful in resolving error code 21001 is to check that the correct operating system is opted to install the VMware tools. This can be checked by connecting to the ESX/ESXi host on which your virtual machine resides. Follow the steps below to check your selected operating system:

1. Firstly, select the virtual machine that you are trying to install tools in.

2. Then, click on the Actions dropdown menu and select the Edit Settings option.

edit settings virtual machine

3. Next, select the Options tab.

4. Now, ensure that the correct guest operating system is selected in the Virtual Machine Properties window.

5. Then, click on OK.

Also Read: How to Enable Virtualization on Windows 10?

Method 5: Verify Corrupt ISO Image

A corrupt ISO image can also cause the error code 21001 while installing VMware tools. Therefore, ensure that your ISO is valid to avoid installation failures using the steps given below:

1. Connect to the ESX/ESXi host.

ESXi Virtual Machine

2. Log in as a user with privileges.

log in ESXi server. Fix VMware Error Code 21001 in Windows 10

3. Now, change the directory to /vmimages/tools-isoimages for VMware ESX/ESXi 3.5.x or above hosts.

4. For older versions of ESX, use /usr/lib/vmware/isoimages.

5. Now, type md5sum xxx.iso and press the Enter key, where xxx represents the ISO image name.

6. Now, record the output for md5sum to check if the ISO image is corrupt.

Also Read: Fix Java Virtual Machine or JVM not found error

Method 6: Manually Install VMware Tools

Sometimes, due to autostart option being disabled, unable to install VMware tools error 21001 can be encountered. In such a case, you can try manually installing the VMware tools to avoid such an error. Follow the steps below to manually start the VMware Tools Installer:

1. Connect to the ESX server or to the VirtualCenter server with the VI client.

2. Now, right-click on the virtual machine you want to install VMware tools on.

3. Next, click on OK or Install when prompted.

4. In case the installer does not start, launch the Run dialog box from the inside guest operating system.

5. Type D:\setup.exe in it.

Type D setup.exe in Run dialog box. Fix VMware Tools Upgrade Error Code 21001 in Windows 10

6. Click on OK to start the installation process of VMware tools.

Hence, these are the methods to fix VMware tools upgrade fails with error code 21001.

Frequently Asked Questions (FAQs)

Q1. Do I need to reboot the system after upgrading VMware tools?

Ans. Upgrading the system is required in case you are using VMware tools with a 5.1 version on a Windows version older than Vista. Also, if you have installed one or more components of VMware tools, then a reboot is necessary.

Q2. Is it necessary to upgrade VMware tools?

Ans. Although updating VMware tools is optional, it is still recommended to install the update for a better VMware experience.

Q3. What is the importance of VMware tools?

Ans. VMware tools are necessary to improve video resolution, color depth, mouse experience, sound, network adapter performance, and more.

Q4. Why is VMware tools installation disabled?

Ans. If VMware tools install is disabled then it can be due to the guest machine not having a virtual optical drive. Also, if your guest system in which you are trying to install VMware tools is already mounted, the issue can be faced.

Q5. Do outdated VMware tools cause an issue?

Ans. Yes, outdated VMware tools can cause issues like elevated CPU utilization or issues with the performance of the system.


All in all, it is safe to say that VMware tools indeed make the operating system work better along with improving many other features. These tools also demand timely updates to keep up the good work. We hope that our guide was helpful in resolving issues like error code 21001 which usually can be encountered while updating VMware tools. Leave your comment down below telling us which one of the methods helped you in doing so. Also, leave your suggestions and queries that you have for us below.

Leave a Comment

Your email address will not be published. Required fields are marked *