In the Windows OS based computer, you get so many applications, programs, features and services to complete the various technical tasks. Windows defender is also one of them. It is introduced by the Microsoft in Windows 10 version. The Windows defender program is a very dynamic one that is used as an antivirus. You can scan the computer and find out errors and corruption in the computer with the help of this feature. But sometimes, when you try to launch the Windows defender program, you get Windows defender error 0x805011011 on the screen of the computer. After getting the defender error code 0x805011011 in the system, you cannot be able to scan the computer to remove virus and infections. In this situation, you can take the help of manual or automatic error troubleshooting recommended here in the article. You can also download and install Advanced System Repair tool in the computer for automatic fixing.