Chrome now respects the Windows setting for zone identifiers and can be configured as shown below.
Global attachment policy
You can change how Windows handles zone identifiers using the group policy editor (
gpedit.msc); the location of these settings is
User Configuration ->
Administrative Templates ->
Windows Components ->
Do not preserve zone information in file attachments was implemented in Chrome as of April 29, 2011 (see Issue 5719).
Changing the default risk of attachments* to low will deactivate the dialog completely and ignore a file's zone security information.
Additionally, you can specify exceptions for certain file extension to, for example, always ask when opening downloaded
Delete zone settings from the command line
If you only want to remove the zone settings from certain files, you can use
streams.exe from the Sysinternals Suite to delete all alternate NTFS data streams:
streams -d <file> and
streams -s -d <directory>
:Zone.Identifier is the stream used to store zone security information.
chromium - Issue 5719: SetInternetZoneIdentifier does not respect the SaveZoneInformation policy
msigeek.com - How to Remove Security Warning Message – Files Downloaded from Internet