windows server 2003 - Active Directory: Accessing network share as WinXP SYSTEM user

The Problem:

I cannot access a Domain Computers-accesible network share by a process running on Windows XP as a SYSTEM account.

I've got a 2008R2 domain, a 2003R2 file server and a set of clients.

On the file server, I've made a share accessible by the Domain Computers group. The share is supposed to hold a read-only repository of files (Wpkg) to be accessed from domain workstations by a system service (Wpkg-GP) run by SYSTEM user.

Now the problem is that, while it works perfectly on Windows 7, it completely fails on Windows XP. It seems, that for some reason the SYSTEM account on Windows XP cannot authenticate as a computer. See more in details.

The Question:

What do I do wrong?

Is it perhaps a natural behaviour of Windows XP system? If so, can it be changed or fixed? Or is there any other way to achieve a scenario, in which a network share would be visible to the SYSTEM user on computers, without being accessible by the users?

The Details:

• The Domain Computers group has received permissions both for the files and for the share


• I have checked higher permissions, all the way from Read to Full Controll


• I have tested the issue with fresh, out-of-the-box operating systems installed on VBox

Since the problem was reported by application, I first began to verify actual SYSTEM user rights. On both Windows versions (7 and XP) I have opened an elevated cmd session impersonating SYSTEM account (using PsExec -s -i cmd.exe) and attempted to manually mount the network share :

net use x: \\myfs.mydomain.com\Wpkg

On Windows 7, the drive has been mounted without demur. But on Windows XP the command responded with information about incorrect password and a prompt for new one:

[Windows XP]
Password for \\myfs.mydomain.com\Wpkg is incorrect.

Please enter password for "myfs.mydomain.com": _

(please note that this is only a translation, an official english locale may sound differently)

Answer

FIXED!

The source of the problem was the fileserver not registering itself into DC DNS. It seems it was apparently done by someone on purpose - the corresponding network interface option has been manually unchecked:

(network interface) 
  -> Properties 
    -> TCP/IP Protocol 
      -> Advanced 
        -> DNS 
          -> [ ] Register this connection's address in DNS

After checking the above option and issuing ipconfig /registerdns:

• fileserver registered properly in DC DNS records


• Windows XP SYSTEM user began to properly mount the problematic share without being asked for credentials

The different behaviour of Windows XP and Windows 7 must be due to some difference in internal implementation; I'd guess Kerberos, though my knowledge of Kerberos is yet superficial.

---

I find it interesting enough to add, that a quite similar thing happens when I try to add a CNAME record from ie. wpkg.domain.mydomain.com to filesystem.domain.mydomain.com:

In Windows XP only the final host name works:

C:\WINDOWS\system32>dir \\wpkg[.domain.mydomain.com]\wpkg
Access denied.


C:\WINDOWS\system32>dir \\fileserver[.domain.mydomain.com]\wpkg
[...result OK... ]

...while on Windows 7 there is nothing against using CNAME:

C:\WINDOWS\system32>dir \\wpkg[.domain.mydomain.com]\wpkg
[...result OK... ]

C:\WINDOWS\system32>dir \\fileserver[.domain.mydomain.com]\wpkg

[...result OK... ]

Note that here I got an Access denied error, not a password prompt.