wmi returns no data from an other pc

[panoss]

I 'm trying to secure my program using the pc 'c data (disk drives and processor).
I use this code:

import wmi
c = wmi.WMI()
for item in c.Win32_PhysicalMedia():
    hdd = hdd + str(item)
for s in c.Win32_Processor():
    hdd = hdd + str(s)
 print(hdd)

It works fine in my pc, but in my client 's pc it returns nothing!
And no error is raised.
Isn't this the correct way to check for disks' and processor 's data?