Actually, you should leave that at it's default setting, with the # of processors box UNCHECKED. Msconfig does not need to know how many cores your CPU has and Windows does not see any benefit or problem from leaving that unchecked. Unchecked is the default configuration. Why would you even be messing around with that in the first place?
What are you trying to accomplish by doing that? The fact is your CPU, which is the same as mine, does NOT have 8 cores. It has four cores but it's architecture allows for four addtional hyperthreads, which are not the same as having 8 cores.