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Microsoft Visual C++ Error 0x80070666: Here’s How to Fix It

A vast majority of Windows apps are written in C++. You may find some apps written in C# or Java but not many fit the bill. C++ apps are far more common. In order for these apps to run though, you must have Visual C++ redistributable installed. Most systems have this installed. You may not remember installing it but it was probably installed by an app that needed it.

The Visual C++ redistributable can be downloaded from Microsoft’s website and installed manually. If you’re trying to manually install Visual C++ installation and you’re seeing the Microsoft Visual C++ installation error 0x80070666, you can fix it with one of the methods listed below.

FIX: Microsoft Visual C++ error 0x80070666

1. Uninstall older versions of Microsoft Visual C++ redistributable

There are several different versions of Microsoft Visual C++ redistributable that users can install. They’re all supported on Windows 10 though newer apps tend to need the newer version of the redistributable. Older versions can interfere with the installation of the newer one so uninstall the old version, and then try installing the new one.

  1. Open Control Panel.
  2. Go to Programs>Uninstall a program.
  3. Look for Microsoft Visual C++ redistributable, select it, and click Uninstall.
  4. Download the Microsoft Visual C++ redistributable and install it.

2. Check for pending Windows updates

‎Microsoft Visual C++ redistributable is essential, so much so that it can be installed via Windows updates. If that’s the case, it’s better to install it via Windows Updates. The update may not explicitly state that it’s installing Microsoft Visual C++ redistributable so make sure you do not have pending Windows updates.

  1. Open the Settings app.
  2. Go to Update & Security.
  3. Select the Windows Update tab.
  4. Click Check for Updates.
  5. Install any updates that are pending/available.
  6. Restart the system and check if Microsoft Visual C++ redistributable has been installed. If not, download and run the installer once you’ve installed all available updates.

3. Run Microsoft’s tool for failed installations

Microsoft knows that sometimes apps fail to install on Windows 10. To counter this problem and give users a simple way to fix it, it has a tool for this very purpose and it can be used to resolve this error.

  1. Download Microsoft’s repair tool from here.
  2. Run the tool.
  3. Apply any fix that it recommends.
  4. Restart the system.
  5. Install Microsoft Visual C++ redistributable.

4. Download Microsoft Visual C++ redistributable again

If you’re using an old installer for Microsoft Visual C++ redistributable i.e., one you downloaded a while back, delete it and download it again. Use the newly-downloaded file to install Microsoft Visual C++ redistributable.

Repair the Microsoft Visual C++ redistributable installer

You may need to repair the installer that you’ve downloaded.

  1. Locate where you’ve downloaded the Microsoft Visual C++ redistributable installer to.
  2. Copy the path to the folder that the installer is in.
  3. Open Command Prompt with admin rights.
  4. Use the CD command to go to the folder that the installer is in.
cd "path to Microsoft Visual C++ redistributable installer"
  1. Run the following command (you may need to change the name of the EXE).
vc_redist.x64.exe /uninstall
  1. Click repair on the window that opens.
  2. Once the repair is complete, run the installer again.


Apps that need the Microsoft Visual C++ redistributable will not be able to run without it. There’s no alternative to it, so resolving problems with the installer is imperative. It’s generally a good idea to install the latest version of Microsoft Visual C++ redistributable especially if you’re running the latest version of Windows 10.

Did this fix it for you?

Let us know if you’re struggling with error 0x80070666, and what worked out for your machine, in the comments below.

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