I've got a windows server 2003 box containing a raid 5 array I use for mass storage. I want to set up a special non-administrator account that can be used to browse files over the network, with only read access. Ideally I'll map my network drive as this user to avoid accidentally hosing my data, and mount as an administrator user on occasions where I actually need write access.

I've created a non-administrator user on the Windows Server box (called "ReadOnly)", and granted the user read permissions on the folders I need. However, when I try to browse to the files, and authenticate as this user, I'm told "Permission denied". If I throw the readOnly user into the administrators group, however, I can authenticate and browse just fine. I am, of course, only attempting to browse to folder for which I have given this user read permissions.

Obviously my ReadOnly user is missing some privilege here, but I can't figure out what it is. I've been digging around in group policy editor all day to no avail. What am I missing?

Fake Edit: I'm doing my browsing from a Windows 7 box, but I don't think that is relevant.