Windows operating system is a very popular and easy to use OS in the world. Microsoft always tries to make it much better than earlier. Recently Microsoft has released the newest version of the operating system i.e. Windows 10. In this update, you get lots of tremendous facilities. Windows defender program is one of them. This is an inbuilt antivirus program that help you to scan the computer and to make it secure from intruders. But sometimes when you try to launch it in the computer, it doesn’t get started and give you Windows defender error 0x80508019. It happens mainly due to the missing or corruption of the system files associated with Windows defender program. After the occurring of this issue, you cannot be able to scan the computer anymore. In this situation, you need to go with some manual or automatic error fixing methods recommended here. You can also download and install the Advanced System Repair Tool for automatic fixing of the issue.