Windows defender is a feature of Windows operating system that is build for the security purpose of the computer. Sometimes when you try to start Windows defender in your computer, you get Windows defender error 0x800704ec. Occurring of the defender error 0x800704ec in Windows happed mainly when the installed antivirus block the starting of Windows defender. Due to the conflicts between antivirus and Windows defender, your computer reaches at a high risk. So, to fix Windows error code 0x800704ec in your computer, you can go with some manual or automatic error fixing methods. Advanced System Repair tool will be the best tool for automatic fixing of the error issue.