I have been fighting with impersonation for quite sometime now and now
matter what I have tried it just won't work.

I am trying to get information on two items:

1)    I'd like to retrieve a file listing from a directory on our file
server.

As with most cases I have read about, it works fine on my development PC, XP
OS, but when ran off of the web server, I receive <error: an exception of
type: {System.UnauthorizedAccessException} occurred>.

The only way I can get it to work is to set impersonation=true and set the
username and password as out system administrator.  I did try to set the
user name and password as an AD user we created with full access to the
directory, but to no avail.

On IIS I have just Integrated Windows Authentication checked.

Web.config is as follows: <identity impersonate="true" />

Code:
Private Sub LoadFiles()

Dim impersonationContext As WindowsImpersonationContext

Dim currentWindowsIdentity As WindowsIdentity

currentWindowsIdentity = CType(WindowsIdentity.GetCurrent, WindowsIdentity)

impersonationContext = currentWindowsIdentity.Impersonate()

Dim dt As DataTable = New DataTable

Dim dr As DataRow

dt.Columns.Add("linkname")

dt.Columns.Add("textname")

Dim di As System.IO.DirectoryInfo

'Dim DirectoryDefault As String =
"\\ussfs01\private\Manufacturing\ProductRequest\" & intRequestNbr & "\"

Dim DirectoryDefault As String = "\\ussfs01\ProductRequest\" & intRequestNbr
& "\"

di = New System.IO.DirectoryInfo(DirectoryDefault)

If di.Exists Then

For Each filename As System.IO.FileInfo In di.GetFiles()

dr = dt.NewRow()

dr("linkname") = DirectoryDefault & filename.Name

dr("textname") = filename.Name

dt.Rows.Add(dr)

Next

Dim dv As DataView = New DataView(dt)

dlAttachments.DataSource = dv

dlAttachments.DataBind()

dlAttachments.Visible = True

End If

impersonationContext.Undo()

End Sub

2)    In the same program I have been trying to retrive the users fullname,
displayname, or given name from our AD.  Once again this works fine on my
Development PC, but on the web server I can't even retrieve those
attributes.

I have tried the following code to no avail:

Dim userkey As String = WindowsIdentity.GetCurrent.Name.Substring(3)

Dim dse As New DirectoryEntry("LDAP://US")

Dim dsearch As DirectorySearcher = New DirectorySearcher(dse)

dsearch.Filter = "(&(objectclass=user)(cn=" & userkey & "))"

dsearch.PropertiesToLoad.Add("displayname")

Dim sr As SearchResult = dsearch.FindOne

If Not (sr Is Nothing) Then

Dim rp As ResultPropertyCollection = sr.Properties

UserName = rp.Item("displayname").Item(0)

Else

UserName = Nothing

End If

I have tried the following code to no avail:

Any help would be greatly appreciated!

James Pemberton