Hi lan,
The unattend.xml IE related settings is described in the article below:
Microsoft-Windows-IE-InternetExplorer
https://technet.microsoft.com/en-us/library/ff715726.aspx
We may also consider to take use of IEAK 11 to build the customized package. Then deploy the package.
Search Providers: Internet Explorer Customization Wizard
https://technet.microsoft.com/en-us/library/dn454909.aspx
And:
IEAK 11: List of tasks and references to create, manage, and deploy Internet Explorer 11 custom packages
https://technet.microsoft.com/en-us/library/dn454958.aspx
Regards
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