On my Vista PC named Jupiter and running Media Center, I logon as Alin and I am able to see shares from another computers (e.g. from a Linux box that is my NAS device). Some of these drives are mapped to local drives on my account, e.g. M:\ -> \\nas\media\music.
I setup my Xbox 360 as a Media Center Extender, however when I go to the Library setup and I try to add a new folder to the library, I am no able to select the shares from my NAS device: in the local drives I only see the C:\ drive, and in the folders shared by other computers I don't see the shares from the Linux box...
Media Center Extender uses a local username named something like MCX1 on the MC PC. It is for this MCX1 user that you have to map a drive to the shared folder to make it appear in the Library as a local drive... This can be done with a NetLogon script.
Start by creating a folder %Windir%\System32\Repl\Import\Scripts. Now create a batch file, where you map the drives. An example might look like this:
@echo off
set CREDENTIALS=/user:LinuxBox\[Username] [Password]
net use P: "\\LinuxBox\media\Pictures" %CREDENTIALS%
net use M: "\\LinuxBox\media\Music" %CREDENTIALS%
Save this file in the folder you created earlier, e.g. as MCXLogonScript.cmd. The location is important. I've read articles this logon file should be placed in C:\netlogon; the help mentions it should be saved in \\vistapc\netlogon share, etc., but none of those worked for me. I found the correct path where Windows was looking for the file with ProcessMonitor, and that path on my Vista box was %Windir%\System32\Repl\Import\Scripts.
It's time to associate the logon script with the MCX1 user. Go to Control Panel -> Administrative Tools -> Computer Management. Under SystemTools/LocalUsersAndGroups/Users, select the MCX1 user and display its Properties. In the Profile tab, type just the file name, MCXLogonScript.cmd.
Go to the XBox 360. Close and reopen Media Center here - it will logout and re-login on the PC with the MCX1 user, and this time it will read the logon script and map the drives. If you go now to Tasks/Setting/LibrarySetup and choose AddFoldersToWatch and select AddFoldersOnThisComputer, now you should see the M:\ and P:\ drives that were mapped by the logon script beside the C:\ drive.
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