PSU bad? Voltage question.

I just built a new computer for my mom, the only parts I used out of her old one was the PSU, HD, Video Card and Wireless card. I replaced her CPU, MB, Ram and case.

Old System
Asus A7V133
Athlon XP 1200
1 gig Ram (originally, then down to 320ish after first PSU died)

New System
Asus A7N8X rev 2
Athlon XP 2400
1 gig ram (new)

But one of the same problems she had with her old computer has followed her to the new one. I reinstalled Win2k (fresh install). Her old computer did this every once in awhile but not often. Her new one is doing it more often (been up and running for 4 days now, done it twice already). I am thinking her PSU has gone bad (again, it died about 6 months ago taking out her ram). I am thinking this new one is dying as well. It isn't a name brand by no means, it is a L&C 350 watt.

It's voltages are:
vcore = 1.66
3.3 = 3.28-3.29
5 = 4.98-4.99
12 = 12.48-12.49

Is that 12 volt too much? A whole half volt over what it should be? I have another L&C 300 watt lying here that I can throw into it to try. (It might be bad to because the system it came out of had a blown capacitors on the MB)

Anyway, when I go in there it is ON (fans, everything running. Monitor is off), but nothing happens when I move the mouse as if it has frozen, monitor won't come back on, nothing. Have to hit the reset button to reboot it.

EDIT:
I came home from work tonight and it was locked up in windows itself. She had about 5 IE windows open and it was froze hard. I had to hit the reset button to reboot it. I think I am gonna throw that 300watt in and see what happens. Would rather not fry this new MB and Ram.

EDIT 2:
Well, I was bored so I went ahead and threw that 300watt in it.

These are it's voltages:
vcore = 1.66
3.3 = 3.26-3.28
5 = 4.89-4.91
12 = 12.28

Are these better? Or should I buy a new one?

EDIT 3:
Guess that wasn't it. Just went in and checked on it and it was locked up again.

I know a few times after it locked it up, the computer complained about the HD. I just assumed it was due to the lock up and not saving everything properly. Guess next thing I am gonna do is replace the HD.

*sigh*

Well to start you are relying, I assume on the readouts from the motherboard sensors itself for these figures you posted? Not allways accurate
Power Supplies are not really expensive even for good name brand ones.
You kept the PSU, HD, Video Card and Wireless card from the original system and its doing the same things basically so.
Its a likely assumption that the PSU isnt delivering the correct voltage or rather enuff.
I would invest in a good namebrand powersupply and out at least that issue out of the mix.

Well, in my edit's I have since replaced the PSU with another PSU (same brand as the old one, lower wattage and it did the same thing).

And yes I was getting the info from the Bios.

Apart from PSU check Processor for temperature threshold crossings, have you checked your hard disk mabbe drive is bad. Also check compatibility of RAM with motherboard and as you have changed motherboard as well you need to test parts thoroughly before putting system togather for usage..
Also look for the thermal decipation method (pad or thermal paste to be used) for AThlon processor and look if you have done job properly..

You can test your RAM using GoldMem Utility.

What I think it is and am testing now is the motherboard drivers I used. If I remember right when I used the Asus A7N8X rev 2 board in my main system I remember reading about how it REQUIRED that you use the Asus version of the drivers rather than the default nVidia ones. I loaded the default nVidia ones. Am uninstalling those now and installing the older Asus 1.16 ones.

Yes, the CPU is fine and so is the motherboard, it came out of my old system. Didn't move anything out of it. Just threw in the PSU from my mom's old system and threw her cd and floppy and hd in it and booted up. The ram "should" be ok but since the problem also occured at times on her old machine I don't think it would be ram but I will eventually check it with goldmem.

Gonna test the drivers and see if that fixes it. If not then will try testing the ram if that is ok then will try a new HD. Her hd is a old 20gig from when 20 gigs were first released. Since it is close to thanksgiving might pick one up for a steal the day after.

It has been my experience that a good brand name power supply is probably one of the solutions to many computer problems. PC Power & Cooling has the "Killer" power supplies, though a bit expensive. Antec makes good ones as well, as do several others. I have, infact, an Antec True Control 2 550 watt, and many problems, including outright failure no longer exist
Jim

Well since I posted last 24 hours ago the computer has been running with no problems. Guess it was a driver issue. Just gonna leave the 300watt in there and keep the 350 as a backup.

Thanks all for your help.