Windows defender is a very marvelous and very dynamic feature included in Windows 10. It will help you to scan the whole computer and to remove the infectious files like virus infections, Trojan, malware, etc. It is used to enhance the computer performance also. But sometimes when you run this feature in the computer, you get Windows defender error 0x8050A003. The defender error code 0x8050A003 may come to you mainly due to missing or deletion of important DLL files or system files associated with the program. It will harm the computer data very much. So, in this case, you must follow the manual or automatic error fixing methods to get rid of the issue. You can download and install Advanced System Repair Tool to fix the issue automatically.