系统。管理访问被拒绝

我正在使用一些代码尝试计算.NET2.0中的处理器数:

internal static int GetNumberOfProcessors()
{
    List<string> list = new List<string>();
    ManagementClass mgmt = new ManagementClass("Win32_Processor");
    foreach (ManagementObject obj in mgmt.GetInstances())
    {
        string item = obj.Properties["SocketDesignation"].Value.ToString();
        if (!list.Contains(item))
        {
            list.Add(item);
        }
    }
    return list.Count;
}

就这样爆炸了:

[ManagementException: Access denied ]
   System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode) +377984
   System.Management.ManagementScope.InitializeGuts(Object o) +654
   System.Management.ManagementScope.Initialize() +162
   System.Management.ManagementObject.Initialize(Boolean getObject) +492
   System.Management.ManagementClass.GetInstances(EnumerationOptions options) +122
   System.Management.ManagementClass.GetInstances() +6

这段代码在卡西尼号的本地运行良好,但在我们的beta服务器上会崩溃。有人知道该怎么办吗?