Toolbars are locked - Unable to customize the toolbar: "Toolbars are locked - Unable to customize toolbar and tool band
When you right-click the standard toolbar in Internet Explorer, the Customize option is missing, and the toolbar options are grayed-out as seen in the picture. This is due to the restrictions set in the registry."
Click Start, Run and type Regedit.exe.
Navigate to the following locations one by one:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
In the right-pane, delete these two values (if exists)