This policy setting allows you to configure the list of low-risk file types. If the attachment is in the list of low-risk file types Windows will not prompt the user before accessing the file regardless of the file's zone information. This inclusion list overrides the list of high-risk file types built into Windows and has a lower precedence than the high-risk or medium-risk inclusion lists (where an extension is listed in more than one inclusion list).If you enable this policy setting you can specify file types that pose a low risk.If you disable this policy setting Windows uses its default trust logic.If you do not configure this policy setting Windows uses its default trust logic.