If you are a Small Business customer, find additional troubleshooting and learning resources at the Support for Small Business site.
When you run Microsoft Windows Defender, you receive one of the following error messages:
Error Code 0x800106ba Application failed to initialize
Error Code 0x800106ba The systems license has expired. Your logon request is denied.
This problem may occur after Windows Defender is updated.
Fix it for me
To fix this problem automatically, click the Fix it button. Then click Run in the File Download dialog box, and follow the steps in the Fix it wizard.
This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
If you are not on the computer that has the problem, save the Fix it solution to a flash drive or a CD and then run it on the computer that has the problem.
Let me fix it myself
To resolve this problem yourself, follow these steps:
Set the Windows Defender service to Automatic instead of Disabled or Manual. To do this, follow these steps:
Click Start, type services in the Start Search box, and then click Services in the Programs list. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
Double-click the Windows Defender service, and then in the Startup type box, click Automatic.
If the procedure in step 1 does not resolve this issue, uninstall and then reinstall Windows Defender. To do this, follow these steps:
Click Start, click Run, type appwiz.cpl, and then click OK.