Are you trying to set permissions on the NAS (it isn't an "external drive" - it is a network attached storage device that you have)?
And, are you doing this because you want to use it as a Centralized Backup location in OneCare?
I'll assume that you are using OneCare.
Your Iomega drive is not attaced to the PC and it is a "mapped drive" in Windows because it is a location on the network - that is the drive is actually a storage server. If you installed software on your PC from Iomega in order for the drive to become drive M on your PC, you'll need to refer to Iomega's instructions on how to set up permissions. You can't share a mapped drive as it is already a Share or network location. Since it is a mapped drive, OneCare treats it as an internal drive, I suspect.
To use the drive for Centralized backup, you need to access the drive this way:
\\server\share where "server" is the name of the device as seen on your network or the assigned IP address and "share" is the name of the Share on the device.
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator
