Hi,
  I am using a NEC powermate 2.8 pentium to contriol my mill
running XP pro and the latest version of mach3 using a netmos pci parallel card.
  The problem I have got is it wont run mach reliably above 25hz.
It does have on board graphics which according to the bios you can disable, but it dosent work ,there are no mobo jumpers.
it does say in bios that you can initiate on pci or onboard.
   But when you get into windows both graphics cards are there.
So my question is if I set to initiate on pci and the main screen to be Pci, although running extend to the onboard will the onboard
graphics still hog memory 512mb (reading 504) and could this be the reason for the frequency unreliability?

Try disabling the one you do not want in the device manager, see if that helps. (;-) TP

There is a Mach III optimization document in the downloads section.  I would suggest downloading it and going through it step by step.  I first set Mach III up on a laptop and even after I got the problems associated with a laptop taken care of (the processor like to slow down), I still had problems with Mach.  Turns out that Apple installs a little program that runs as a service when you install Quicktime.  I forget the name of it, but all it is good for is sucking up a bunch of processor power and making Mach hiccup.  Some folks have had problems with on-board graphics, but I have had good luck so far.  If your using the PC for other things besides Mach, you might consider making it a dual boot machine; install a basic XP install on another hard drive (or partition) that is optimized for Mach III, boot to it when machining.