First, we had not seen the CPU fan check used before, and upon testing the WMI query in a VMware Windows 7 virtual machine we saw no result, as seen in Figure 1  Figure 1 WMI query for the Win32_Fan class on a VM returning no statistics However, when we ran the same query in a physical system running Windows 7, we saw the contents of the Win32_Fan class, as seen in Figure 2