Count The Number Of Processors In .NET 2.0 - System.Management Access Denied

I was using some code to try to count the number of processors in .NET 2.0:

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;
}

and it blew up like this:

[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

This code runs fine locally on cassini, but blows up on our beta server.