I have Windows 7 64 bit, and I run from Visual Studio 2010 Professional.
Hmmm... I've not used VS, but I think you could open a command prompt window and
<run your .exe>
Also, why would 1 core (which goes through the OpenMP loop once per trip) run faster than 0 cores, which does the same thing but not inside an OMP construct?
Ups! I didn't realize about times for 0 and 1 values of CORE... I can't see the relationship among values 0 and 1 with the number of cores used at runtime...