Microsoft made a lot of improvements when they released Office 2007. A lot of those improvements deal with security to protect the user. With a lot of phishing scams and other attacks that are carried out through email, this is a really nice enhancement. Unfortunately, for power users, some of these enhancements hinder the functionality they are looking for. One of these features is the new Hyperlink Security Warning. This feature will display a warning box every time the user clicks on a hyperlink that points to a file on the local file system. It requires the user to allow or deny the action. I would agree that in general this is a good feature to have because it is not common practice to receive emails that have hyperlinks to local files. For some users of our Attachment Save program, we have found that the warning only inhibits the add-in. The add-in saves the attachments in email to the local hard drive and replaces them with a hyperlink. With the new warning message, every time a user wants to reference the file from the email they are prompted with a request for confirmation.
Fortunately, there is a workaround for this situation. I must warn you that making the changes I will reference will create a security risk and is only recommended for users that understand what they are doing. You can find the workaround in this KB Article. The solution requires modifying the registry by adding a new security key named DisableHyperLinkWarning and setting the value to 1. Be careful changing this value as it will disable all hyperlink warnings in all of your Office 2007 programs.