protected PerformanceCounter cpuCounter; 
protected PerformanceCounter ramCounter; 

cpuCounter = new PerformanceCounter(); 

cpuCounter.CategoryName = "Processor"; 
cpuCounter.CounterName = "% Processor Time"; 
cpuCounter.InstanceName = "_Total"; 

ramCounter = new PerformanceCounter("Memory", "Available MBytes"); 

/* 
Call this method every time you need to know 
the current cpu usage. 
*/ 

public string getCurrentCpuUsage(){ 
            cpuCounter.NextValue()+"%"; 
} 

/* 
Call this method every time you need to get 
the amount of the available RAM in Mb 
*/ 
public string getAvailableRAM(){ 
            ramCounter.NextValue()+"Mb"; 
}