In your Windows operating system based computer, you may find so many features and services that help you to make your work so easy. In the latest release of Windows version i.e. Windows 10, you get so many amazing features. Windows defender is also one of them. This program is just like an antivirus that helps you to scan the computer and to remove infectious files or apps properly. Sometimes while you try to launch this program, you may get Windows defender error 0x80509001. Occurring of the defender error code 0x80509001 will harm the computer data very much and make you unable to access the computer properly. In this situation, you should go through some manual or automatic error fixing methods to fix Windows error code 0x80509001. For automatic fixing, you can download and install Advanced System Repair Tool in the computer.