How to Fix Installer Error 1721? Solutions For Windows 7/8/10

Windows users have some problems when they try to run Java or other similar programs. Error 1721 with the Windows setup is one of them.

This problem usually shows up when you try to install or remove a program, when your computer can’t read certain files, or when the Windows installer package isn’t working right. After that, this problem message shows up.

Error 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor.

You may be one of the users who is having this problem and is reading this post to find a solution.

You can get around the Windows 10 Installer error 1721 by following the steps in this guide.

How to Fix Windows 7/10 Installer Error 1721?

Well, the following methods will make it easy to fix Windows installer error 1721 so that you can start the installation process again.

Solution 1: Disable the Internet Explorer add-ons

You can fix the installer problem 1721 by turning off the Internet Explorer add-ons. To do that, follow the steps below:

  • Start up the Internet Explorer.
  • Press the “Tools” button.
  • Click on Manage add-ons.

Solution 1: Disable the Internet Explorer add-ons

  • Click on Add-ons that Internet Explorer has used in the Manage add-ons window. Then, click on each add-on in the list.

Solution 1: Disable the Internet Explorer add-ons

  • Once you’re done, click “OK.”
  • A message will be sent to you. When you’re done making changes, you may need to close Internet Explorer, click OK, and then open it again.

Turn your computer off and on again, then try to run a program and see if the error 1721 Windows 7/10 still shows up.

Solution 2: Disk Cleanup

That is a computer maintenance tool called “disk cleanup” that will help get rid of the files on the drive that are causing the setup error 1721.

  • Click on the Windows button.
  • Find “disk cleanup” and click on the link that comes up.

Solution 2: Disk Cleanup

  • Pick out the drive that needs to be cleaned up, then click “OK.”
  • Under “Files to Delete,” click on the file you want to get rid of, then click “OK.”

Solution 2: Disk Cleanup

  • If you want to get rid of files, click on Clean Up System Files and then click on OK.

Once you’ve cleaned up your disk, try installing a program again to see if the error 1721 Windows launcher is gone.

Solution 3: Create a restore point

To get rid of Windows 10 installer problem 1721, try changing your system back to the version of Windows that you had before.

  • Type “make a restore point” into the Windows search bar and click on it.

Solution 3: Create a restore point

  • Click on “System Restore” in the “System Properties” window.
  • Pick a point in time when your computer was last fixed.
  • To get rid of apps you no longer need, click on Scan for affected programs.

Solution 3: Create a restore point

  • Press “Next.”
  • When you get to System Restore Windows, click on Next.
  • Press “Finish.”

After following these steps, your computer will be back to how it was before the error 1721 happened, and you will no longer see the software error.

Solution 4: Re-register the Installer

To fix this problem, all you have to do is re-register the Windows installer. After that, the software error 1721 will go away.

  • To begin, start up Windows in safe mode with administrative rights.
  • After that, click on the Windows button, type cmd, and then right-click on it. Choose Run as administrator.
  • Enter the following commands into the command prompt and press return:

msiexec u/unregister

msiexec /register

When you do these steps, the Windows software will be registered again, and the error 1721 Windows 10 will be fixed.

Solution 5: Update Windows Installer

A lot of people need to know what version of the software they’re using or if it’s been changed. Windows Installer 4.5 is the most recent version of the installer.

If you get the Windows setup error 1721, it could be because the software you are using is out of date. To fix this problem, get the new version and try to update it.


That was all about how to fix a Windows startup Error 1721. Here is a list of things that can be done to fix the setup problem 1721. If the instructions are hard for you to follow, take the easiest way out to fix the problem.

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