I'm using the flowing code, but it says that category does not exist.
static PerformanceCounter cpuUsage;
public static void Main(string[] args)
{
cpuUsage = new PerformanceCounter("Processor", "% Processor Time", "_Total");
Console.WriteLine(cpuUsage.NextValue() + " %");
Thread.Sleep(1000);
Console.WriteLine(cpuUsage.NextValue() + " %");
Console.Read();
}