This guide will show you how to resolve Windows Installer error 1721 when trying to install the ExpressVPN app:
Error 1721. There is a problem with this Window Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor. Action: Uninstall3x, location: C:\Program Files (x86)\ExpressVPN\Uninstall.exe, command: /S"_?=C:\Program Files (x86)\ExpressVPN\""
If you encounter this error, you will not be able to install the ExpressVPN app.
To resolve the issue:
- Download and open the Microsoft Install and Uninstall Troubleshooter.
- Click Uninstalling.
- Click ExpressVPN > Next.
- Click Yes, try uninstall.
- Wait for the ExpressVPN app to uninstall. Once complete, a message that reads “fixed” will appear. Click Close.
- Go to Settings > Apps. Check if ExpressVPN still appears on your Apps list. If yes, select it and click Uninstall.
The ExpressVPN app is now uninstalled on your device. Download and install the ExpressVPN app for Windows normally.