In your Windows computer, you may get many features and service to complete your various technical tasks. Windows is used to complete the personal or professional requirements. Microsoft uses to release updates time to time for Windows versions. In the latest version of Windows 10, you get Windows defender program that acts as an antivirus to scan and remove the infections. It also enhances the computer performance as well. But sometimes when you try to launch the program, you get Windows defender error 0x80509003. In this situation, your computer becomes inaccessible and gives many other error messages too. Therefore, you should go with some error troubleshooting processes to get rid of defender error code 0x80509003. You can run Advanced System Repair Tool for automatic fixing of the issue.