How I can be able to cut the VCore voltage to the CPU (P4) for a period of time (when booting up) and re enable it after a delay of time. I need this so the cooler can cool my CPU before I turn it on.
Well instead of using a normal reset switch you can try using one that stays closed after pressing it so your motherboards stays resetting... but I dunno if this will shut-off the CPUs power.
Another way will mean serious modding on your motherboard and I have no idea if that would eventually work without destroying your components.
Why do you want such a system?
My dual-PSU PC is so powerfull that the neighbourhood dims when I turn it on
There is something out there I've seen that plugs a small chip into your mainboard plug and keeps the system in continual reset until a desired temp is reached. It has a thermistor attached so when it gets to whatever temp you want, it brings it out of the loop.
For those of you who don't know, this is common if someone is using a compressor to cool their CPU. This lowers the CPU temp to around -45C so the chip doesn't cook when you crank your 3.06 to 4.2 right from a normal start.
Though, I must say, compressors are big, bulky, and practical if you are never going to move your computer. Ever. Frankly, I don't think the performance gain is worth it.
XP 2500+ Barton @ 2241Mhz
2x512MB Corsair PC3200
MSI GF3Ti 500
2x80GB 7200RPM Maxtor