Hey, is there anyone how get experiences with this class. I try to use it, in a normal way like this: ManagementObjectSearcher mang = new ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive"); foreach (ManagementObject obj in mang.Get()) { MessageBox.Show(Convert.ToString(obj["Description"])); } Here, i used the DiskDrive-Class, and all work fine, but if i try to use the PhysicalMediaClass in the equal way, the output just gives me a zero-string. what´s my mistake?? can anyone help me??? holzmcgyver