Bob
XP Professional supports 2 physically separate processors and
hyper-threading.
If it is working properly, with Hyper Threading enabled, then it should look
like there are 4 CPUs present - 2 logical (or virtual) CPUs for each
physical processor.
XP Home, on the other hand, does *not* support physically separate
processors. It does, however, support hyper-threading which creates 2
logical (or virtual) processors which share the workload. In such a case 2
identical logical processors will be seen.
hope that helps
Pete