0x80070643Microsoft Windows Installer

How to Fix 0x80070643 (Microsoft Windows Installer)

Quick Answer

Error code 0x80070643 indicates a fatal error during a Microsoft Windows Installer installation. This often points to issues with the .NET Framework, corrupted system files, or interference from security software. The fastest fix often involves repairing the .NET Framework installation or performing a Windows Update troubleshooting.

What Causes This Error

Corrupted or damaged .NET Framework installation.
Interference from antivirus software or firewall.
Corrupted system files or Windows Installer service issues.
Issues with Windows Update components.
Insufficient permissions for installation.
Previous failed installation attempts leaving residual files.

Step-by-Step Fixes

1Run the Windows Update Troubleshooter

Open the Start menu and type 'Troubleshoot settings', then select the appropriate option.
Click 'Additional troubleshooters' or 'Other troubleshooters'.
Locate 'Windows Update' in the list and click 'Run the troubleshooter'.
Follow the on-screen instructions and apply any recommended fixes.
Attempt the installation again after the troubleshooter completes.

2Repair or Reinstall the .NET Framework

Open the Control Panel by searching for it in the Start menu.
Navigate to 'Programs' > 'Programs and Features' or 'Uninstall a program'.
Look for Microsoft .NET Framework entries. Note that some versions are integrated into Windows and cannot be uninstalled separately.
For versions that can be uninstalled, select them and choose 'Uninstall/Change'. Follow prompts to repair if available, or uninstall and then reinstall the specific .NET Framework version required by the application.
Alternatively, download and run the Microsoft .NET Framework Repair Tool from the official Microsoft website, then attempt the installation again.

3Temporarily Disable Antivirus Software and Firewall

Locate your antivirus software icon in the system tray (usually bottom-right of the screen).
Right-click the icon and look for options like 'Disable', 'Pause protection', or 'Exit'. Select an option that temporarily disables real-time protection.
Open the Start menu, search for 'Windows Defender Firewall with Advanced Security', and open it.
In the left pane, click 'Windows Defender Firewall Properties'. For each profile (Domain, Private, Public), set 'Firewall state' to 'Off'. Click 'Apply' and 'OK'.
Attempt the installation. Remember to re-enable your antivirus and firewall immediately after the installation attempt, regardless of success.

4Run System File Checker (SFC) and DISM

Open the Start menu, type 'cmd', right-click 'Command Prompt', and select 'Run as administrator'.
In the Command Prompt window, type 'sfc /scannow' and press Enter. Allow the scan to complete.
After SFC finishes, type 'DISM /Online /Cleanup-Image /RestoreHealth' and press Enter. Allow this process to complete.
Restart your computer after both scans have finished.
Attempt the installation again.

Advanced Fixes

Reset Windows Update Components

Open the Start menu, type 'cmd', right-click 'Command Prompt', and select 'Run as administrator'.
Stop the BITS, Windows Update, and Cryptographic Services by typing the following commands, pressing Enter after each: 'net stop bits', 'net stop wuauserv', 'net stop appidsvc', 'net stop cryptsvc'.
Delete the qmgr*.dat files by typing 'Del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"' and pressing Enter.
Rename the SoftwareDistribution and catroot2 folders: 'Ren %systemroot%\SoftwareDistribution SoftwareDistribution.old' and 'Ren %systemroot%\system32\catroot2 catroot2.old'.
Restart the BITS, Windows Update, and Cryptographic Services by typing: 'net start bits', 'net start wuauserv', 'net start appidsvc', 'net start cryptsvc'.
Close Command Prompt and restart your computer. Then, attempt the installation.

Frequently Asked Questions

What does error code 0x80070643 mean?

Error code 0x80070643 indicates a 'fatal error during installation' for software using the Microsoft Windows Installer. It often points to underlying system issues rather than a problem with the installer itself, such as corrupted files, .NET Framework issues, or security software interference.

Is 0x80070643 a serious error?

While it prevents software installation, 0x80070643 is generally not indicative of a critical system failure. It can usually be resolved by addressing common underlying issues like corrupted system components, Windows Update problems, or conflicts with other software.

Can antivirus software cause 0x80070643?

Yes, antivirus software or firewalls can sometimes interfere with the installation process, leading to error 0x80070643. They might incorrectly flag installer files as malicious or block necessary system changes. Temporarily disabling them during installation can help determine if they are the cause.

How do I prevent 0x80070643 from happening again?

To minimize the chances of encountering 0x80070643, ensure your Windows operating system and .NET Framework are up to date, run routine system file checks, and maintain a reliable antivirus solution that does not excessively interfere with legitimate software installations.