As per the intel documents the CPU Intel III onwards does contain the CPU Serial number.
I have tried most of the things and on multiple PC's could not able to read the serial
with EAX =3 and CPUID instruction on all PCs the CPUID is disabled ie EAX =1 and CPUID
and the EDX 18 the bit is always "0".
Does any body have any Idea how to enable the cpu serial ?