How to Fix Error 1720 (Windows Installer)
Quick Answer
Error 1720 indicates a problem with a Windows Installer package, specifically that a script required for installation could not be executed. This often points to issues with Windows Installer service, permissions, or corrupted installation files. The fastest fix often involves ensuring the Windows Installer service is running correctly and checking file permissions.
What Causes This Error
- Corrupted or incomplete installation package.
- Insufficient user permissions to execute scripts or access temporary directories.
- Problems with the Windows Installer service (e.g., not running, corrupted).
- Conflicting background processes or security software interfering with the installation.
- Issues with temporary folders where installer scripts are extracted.
- Damaged system files or registry entries related to Windows Installer.
Step-by-Step Fixes
1Verify Windows Installer Service Status
- Press the Windows key + R to open the Run dialog.
- Type "services.msc" and press Enter to open the Services window.
- Locate "Windows Installer" in the list of services.
- Check the 'Status' column. If it is not 'Running', right-click on 'Windows Installer' and select 'Start'.
- If it is already running, right-click and select 'Restart'.
- Attempt to run the installation again.
2Run Installer as Administrator
- Navigate to the location of the installer file (.msi or .exe).
- Right-click on the installer file.
- Select "Run as administrator" from the context menu.
- Follow the on-screen prompts to complete the installation.
- This grants the installer elevated permissions, potentially resolving Error 1720.
3Clear Temporary Files
- Press the Windows key + R to open the Run dialog.
- Type "%temp%" and press Enter to open the temporary files folder.
- Select all files and folders within this directory (Ctrl + A).
- Press the Delete key to remove them. Skip any files that cannot be deleted.
- Close the temporary files folder and attempt the installation again.
4Re-download or Obtain a New Installer Package
- If the installer was downloaded, delete the existing file.
- Download a fresh copy of the installer package from the official source or vendor website.
- If using a physical disk, ensure it is clean and free of scratches.
- Attempt the installation with the new package.
- Corrupted download files can often lead to scripting errors during installation.
5Disable Antivirus/Firewall Temporarily
- Locate your antivirus or firewall software icon in the system tray (bottom-right corner of the screen).
- Right-click the icon and look for options like "Disable protection," "Pause protection," or "Turn off firewall."
- Temporarily disable these protections for the duration of the installation.
- Attempt to run the installer again.
- Remember to re-enable your security software immediately after the installation is complete.
Advanced Fixes
Register Windows Installer Components
- Press the Windows key + R to open the Run dialog.
- Type "msiexec /unregister" and press Enter. A command prompt window may flash briefly.
- Press the Windows key + R again.
- Type "msiexec /regserver" and press Enter. Another command prompt window may flash.
- Restart your computer.
- Attempt the installation after the restart. This re-registers the core Windows Installer components.
Run System File Checker (SFC)
- Press the Windows key, type "cmd", right-click on "Command Prompt", and select "Run as administrator".
- In the Command Prompt window, type "sfc /scannow" and press Enter.
- Allow the scan to complete. This process checks for and repairs corrupted Windows system files.
- Once the scan is finished, restart your computer.
- Attempt the installation again. Corrupted system files can impact installer functionality.
Check and Adjust Folder Permissions
- Navigate to the 'C:\Windows\Installer' folder. If you cannot see it, ensure 'Show hidden files, folders, and drives' is enabled in Folder Options.
- Right-click on the 'Installer' folder, select 'Properties', then go to the 'Security' tab.
- Click 'Edit' and then 'Add'. Type 'Everyone' in the object names box and click 'Check Names', then 'OK'.
- Ensure 'Everyone' has 'Read & execute' and 'List folder contents' permissions. Apply changes.
- Repeat this process for your temporary folder (access via %temp% in Run dialog) ensuring your user account has full control.
- Attempt the installation again after adjusting permissions.
Frequently Asked Questions
What does 'Error 1720' specifically mean?
Error 1720 indicates that the Windows Installer encountered a problem executing a script that is critical for the installation process. This script could be embedded within the installer package or referenced by it, and its failure prevents the installation from completing.
Is Error 1720 always related to Windows Installer?
Yes, Error 1720 is a specific error code generated by the Windows Installer service. While the underlying cause can vary (permissions, corrupted files, service issues), the error itself directly points to a failure within the Windows Installer framework.
Can antivirus software cause Error 1720?
Yes, antivirus or firewall software can sometimes interfere with the execution of installer scripts, flagging them as potentially malicious or blocking their access to system resources. Temporarily disabling security software can help determine if it is the cause.
Do I need to restart my computer after applying these fixes?
While not always strictly necessary for every step, restarting your computer is often a good practice after making system-level changes, such as re-registering services or running system file checks. This ensures all changes are properly applied and system resources are refreshed.