WMI kald til server

Hej alle

Er der nogen der kan fortælle mig hvorfor nedenstående fungere ved kald til bruger-pc'ere, men ikke på mine servere (kalder med en admin-konto):

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    public string FreeSpace(string HostOrIP, string username, string password)
    {
        ConnectionOptions myConnectionOptions = new ConnectionOptions();
        myConnectionOptions.Impersonation = ImpersonationLevel.Impersonate;

        if (username != null && password != null)
        {
            myConnectionOptions.Username = username;
            myConnectionOptions.Password = password;
        }

        ManagementScope objwmiservice;
        ManagementObjectSearcher myObjectSearcher;
        ManagementObjectCollection myCollection;

        try
        {
            objwmiservice = new ManagementScope((@"\\" + HostOrIP + "\\root\\cimv2"), myConnectionOptions);
            objwmiservice.Connect();
            myObjectSearcher = new ManagementObjectSearcher(objwmiservice.Path.ToString(), "SELECT FreeSpace, Size, Name FROM Win32_LogicalDisk WHERE DriveType = 3");
            myObjectSearcher.Options.Timeout = new TimeSpan(0, 0, 0, 0, 7000);
            myCollection = myObjectSearcher.Get();

            foreach (ManagementObject myObject in myCollection)
            {
                if (myObject.GetPropertyValue("FreeSpace") != null)
                {
                    string receiver = "[CurrentUser]";
                    if (myConnectionOptions.Username != null)
                        receiver = myConnectionOptions.Username;

                    long Userx = Convert.ToInt64(myObject.GetPropertyValue("FreeSpace"));
                    return "Free space on '" + HostOrIP + "': " + (Userx / (1024 * 1024 * 1024)) + " GB."
                        + " (Read by '" + receiver + "'.)";
                }
            }
            return "Info not found.";
        }
        catch (UnauthorizedAccessException e)
        {
            return e.ToString(); //e.Message.Substring(0, e.Message.IndexOf("("));
        }
        catch (Exception e)
        {
            return "UNKNOWN ERROR:<br />" + e.ToString();
        }
    }

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Får følgende access denied fejl:

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System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)) at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) at System.Management.ManagementScope.InitializeGuts(Object o) at System.Management.ManagementScope.Initialize() at System.Management.ManagementObjectSearcher.Initialize() at System.Management.ManagementObjectSearcher.Get() at WMI_call.FreeSpace(String HostOrIP, String username, String password)

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