Help about the Processors

Here you go

A very good tutorial by Brink. Of course.

Boot Advanced Options - Number of Processors

I suggest making your system like my picture in post#4 and see if it helps. Both my system are that way and things work as they should.
If for what ever reason you don't like it you can always put it back the way you want it.

Using System Configuration (msconfig) - Windows Help

Number of processors. Limits the number of processors used on a multiprocessor system. If the check box is selected, the system boots using only the number of processors in the drop-down list.

Maximum memory. Specifies the maximum amount of physical memory used by the operating system to simulate a low memory configuration. The value in the text box is megabytes (MB).