It looks to me like you have 2 different kernel versions for RedHat. One is for a regular, everyday PC with one processor. The other one (with the SMP in it) is for a computer with more than one processor. Symmetic Multiple Processing (I think, or something similar anyway), SMP. I think you know what the Windows XP one does (or I hope so, at least.) Just a note, you can use either version of those two kernels without much of a difference, I think. If you run an SMP kernel, or a kernel with SMP compiled into it, it will still run on a computer with one processor.