Bob Knowlden wrote:

I've done this exactly once, but XP automatically detected the dual-core CPU
and installed the multiprocessor HAL for it. (This was XP Home Edition, with
SP2 slipstreamed onto it.)

Verify afterwards that two CPUs appear in Device Manager, and/or that you
get two CPU usage plots in the Performance tab of Windows Task Manager
(cntl-alt-del).



cntl-alt-del or cntl-shft-esc.