SetProcessAffinityMask( hProcess, 1L );// use CPU 0 only
SetProcessAffinityMask( hProcess, 2L );// use CPU 1 only
SetProcessAffinityMask( hProcess, 3L );// use CPU 2 only
SetProcessAffinityMask( hProcess, 4L );// use CPU 3 only
SetProcessAffinityMask( hProcess, 5L );// allow running on all CPUs
If you have 2 processors both masks should be 3 by default. You can then use the calls
SetProcessAffinityMask( hProcess, 1L );// use CPU 0 only
SetProcessAffinityMask( hProcess, 2L );// use CPU 1 only
SetProcessAffinityMask( hProcess, 3L );// allow running on both CPUs