File download from unknown zone in Internet - I am in problem after unckecking the Security message?

while attempting file download from Unknown Zone, a small yellow box comes up with 3 options 'Open' 'save' 'cancel' along-with a security caution at the end, and a checkbox(with default checkmark) containing a message 'Always ask before opening this type of files' . I am in great problem after I unckecked the checkbox. All large files with that particular extension(.csv) are opening direct on my browse. However, this unchecking has not affected opening of files with other types of extensions (.dbf etc.) in unknown zone, and they are displaying the 'warning message' as usual. Changes made in Security-Privacy-View-Display Settings etc., failed to restore Original settings for that particular type of file download. Direct downloads from UnknownZone without having a chance to Review the file is a security threat to my computer.

How can I restore back to my Original Settings ?

File download from unknown zone in Internet - I am in problem after unckecking the Security message?liveupdate

well there are many options. the best one would be to check system restore in control panel. and restore the os to a previous date. you can also make a disk partition and isntall another os, then tranfers your old files to the new os. Also dont mind much about that box that comes up when you try to download a file. its only a warning it doenst do anything. get a firewall and customize it to do this instead of that useless box.