Sudden Power Failure Installing Windows

[Egocynn]

This is my first build. Here are the specs:

AMD Athlon 64 3200+ Venice
MSI K8N Neo4-F Socket 939 NVIDIA nForce4 ATX AMD
WestDig Caviar 250GB SATA
CORSAIR 1GB (2 x 512MB) (only one installed for trouble shooting)
NEC 16X DVD±R DVD Burner Silver IDE

All installation went ok. Fans run, components detected in BIOS, temp fine. Trying to boot Windows from optical drive, the initial drivers install and the SATA/RAID extra drivers on the diskette load as well (F6 and MSI-provided disk). However, when Windows asks about partitioning the hard drive, the system suddenly powers down before I offer a command.

I have not swapped out the power supply. It is an unknown brand for me and provides 350W. I picked up an Antec to swap and will try that tonight. BIOS upgrad? MSI mainboard drivers needed? Why would Windows' set up force a power down when interacting with the hard drive (which is larger than Windows expects, being 250 Gb)?

[ITTechnician]

sounds like to much power for your power supply.
Also by looking at ya hard ware those do take allot fo energy so you might wanna get a new power supply 350 watts or higher.

im sure thats what it is....thats a rather good machine there

ok i see that your power supply is 350 watts wait are u sure.......
well i'll do more research but im pretty sure it might be your power supply.

I'll research it for ya.

[Egocynn]

Yes. I'm pretty happy with it. Will be more so when it works. I've spent about a week and a half working around smaller issues and reading. And reading. My ability for casual conversation with non-tech types has dwindled.

I went through a basic power supply calculator and came up with 265. They didn't list the vid card nor did they make a distinction between high capacity hard drives (don't know if that matters). So even adding 50 watts to the total draw, seems like the sheer size of the wattage allotted by the present pow sup should cover it. Regardless, I'm trying the Antec tonight. Might just be bad. Below is the calculator I used.

http://www.jscustompcs.com/power_supply/

[GX1_Man]

350w is the bare minimum to try and run that and more makes a LOT of sense. The important thing is the amps on the 12v rail, but it sounds like no way to check that? Antec is a good brand but there is no sense in skimping on this vital component of your dream system. Those calculators are just ballpark guesses. What kind of video card is on there? If you say PCIe 350w is ridiculous!  

[Egocynn]

Thanks for the responses. Yes, it is PCIe. My Vid card is in the slot.

I looked into the mainboard specs and it requires at least 18A on the 12 Volt (4 pin) power connector. The previous p supplies had less than this. I just grabbed a power supply with a 20A rating and 400 Watts. Same thing. Got a little further in the Windows set-up procedure. Sudden power shut-down at the user agreement and coming up on the hard drive partitioning.

Can anyone suggest a power supply with a strong Amp rating on the 12 Volt? Does this sound like the mainboard is failing somehow? An issue with communication from the opt drive to the SATA?

Main question: Why do some p supplies list two different 12V ratings? I noticed this when looking for a better P Sup. The highest single 12V rail I could find was 20A. Other supplies had two different ratings like 19A and 17A. Should I assume these work collectively or at least split up the power needs of my CPU, PCIe Vid Card (no direct power; only through Mobo), fans SATA and optical drive?

If I understand the power dynamics, a 20A 12V should make 240 Watts available to be used by all the components looking to the 12V for power. Need more? Hayzeus, I'm frustrated.