I am using SmartPart to Load User Controls (.ascx) in a SharePoint
Page. In the code I am trying to access External resources such as File
System. When non-admin users try to the access the page, they are
getting a 403 forbidden error but for admins who have admin privileges
on the Server, they do not get any errors. I tried to use
SPSecurity.RunWithElevatedPrivilges around the code that is accessing
the File system but it didnt work. I tried to even impersonate a super
user who is an admin on the server but of no use. The Impersonated
credentials are not making all the way through.

One of my options is to give the domain users Read access to the Web
folder, I tested this and it is working but I dont know if this is the
right solution.