FIX: Visual C++ error 0x80070666 on Windows 10 & 11

Matthew Adams
by Matthew Adams
Windows & Software Expert
Matthew is a freelancer who has produced a variety of articles on various topics related to technology. His main focus is the Windows OS and all the things surrounding it. He is passionate about... Read more
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  • If you encounter the Visual C++installation error 0x80070666, be sure to remove components that might interfere with it.
  • Repairing the previous installation can sometimes help with this issue.
  • Keeping your system up to date is a great way of dealing with all sorts of problems.

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0x80070666 is a Microsoft Visual C++ installation error. The issue arises for some users when they try to install Visual C++ Redistributables on Windows. The full error message states this:

One or more issues caused the setup to fail… 0x80070666 – Another version of this product is already installed. Installation of this version cannot continue. To configure or remove an existing version of the product, use the Add/Remove Programs.

Users can’t install the required Microsoft Visual C++ package when this happens. The error message, however, does provide a subtle hint as to how to fix the issue.

Doing so is simpler than you think, and in today’s guide, we’re going to show you the best way to handle this problem.

Why does the Microsoft Visual C++installation error 0x80070666 appear?

In most cases, this error appears due to software conflicts on your PC. Sometimes older versions of Visual C++ can lead to this and many other errors.

In other instances, it’s possible that your installation is damaged, so it’s advised to repair it in order to avoid these types of issues.

How do Microsft Visual C++ Redistributables work?

Visual C++ Redistributables will install C and C++ runtime libraries. These are used in order to run certain applications that are made with these programs.

In case you don’t have the necessary libraries, the application won’t be able to start until you install them.

How do I fix Visual C++ error 0x80070666 on Windows 10 & 11?

1. Uninstall Visual C++ packages already installed

  1. To fix that, press the Windows key + R hotkey.
  2. Type appwiz.cpl in the Open text box and click OK.
  3. Select a Microsoft Visual C++ package to uninstall, then click Uninstall.
  4. Then go through the uninstall guidelines to remove the software.
  5. Repeat steps three to five to uninstall all Visual C++ packages.
  6. After doing that, restart your PC and try to install the desired package again.

2. Check for Windows updates

  1. To check for Windows updates, press the Windows key + S keyboard shortcut.
  2. Type the keyword updates in the search box. Click Check for updates.
  3. Then press the Check for updates button. Windows 10 will download pending updates.
  4. Thereafter, you’ll need to restart Windows.

3. Repair the Visual C++ installer

  1. Press Windows key + R and enter appwiz.cpl. Press Enter.
  2. Select the version fo Visual C++ Redistributable that you want to repair and click Change.
  3. Select Repair.
  4. Follow the instructions on the screen to complete the process.
  5. Do this for all other versions of Visual C++ Redistritubatbles.

4. Check out the Program Install and Uninstall troubleshooter

  1. Visit Microsoft Installation Troubleshooter page.
  2. Click on Download troubleshooter.
  3. Open the troubleshooter’s window, and click Advanced.
  4. Select Apply repairs automatically and click Next.
  5. Select the Installing option.
  6. Select the Visual C++ package that error 0x80070666 arises, and press the Next button.
  7. Wait for the process to finish.

How can I fix the Visual C++ error 0x80070666 on Windows 11?

Repair installation with the Terminal

  1. Make sure you have Visual C++ Redistributables downloaded and saved to the Downloads directory.
  2. Press Windows key + X and choose Windows Terminal (Admin).
  3. Run the following command: cd C:\Users\WindowsReport\Downloads
  4. Now run the following command: vc_redist.x64.exe /uninstall
  5. Select the Repair option.
  6. Follow the instrictions on the screen to complete the process.

Does Windows have Visual C++ Redistributables preinstalled?

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No, Windows doesn’t have Redistributables preinstalled, but there’s a good chance that your PC already has them.

Almost all applications will automatically install the necessary components when you install them, thus allowing the application to work properly.

  1. Go to the Microsoft download page.
  2. Locate the version that you want to download and click it.
  3. Once the download is finished, run the downloaded file.
  4. Follow the intructions on the screen to install it.

Do I need to have all versions of Visual C ++ Redistributables installed?

This depends on the application you’re trying to run. In general, it’s always better to have more versions installed since you’ll ensure maximum compatibility.

However, it’s absolutely not mandatory to have all versions installed, and even if you miss one, it’s easy to download and install.

Those are a few of the more widely confirmed resolutions that have fixed error 0x80070666 for users. So, they’ll probably resolve the issue so you can install the required Visual C++ package.

In case you still have problems, check our Cannot install Visual C++ 2015 Redistributable guide for more solutions.

If you are aware of another fix for this issue, help the other users by sharing it in the comments section below.

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Frequently Asked Questions

  • Microsoft Visual C++ is an integrated development environment used to create Windows applications. It contains all the libraries that an app written in C++ needs in order to run.

  • In simple terms, a runtime error is an error message that triggers during a program’s run. Microsoft Visual C++ can also be the subject of runtime errors.

  • Yes, any program can encounter runtime errors, including games that use Microsoft Visual C++.