Power supply - ATX or not? (Using Everest)

You need to list the specs; example-dell model number or motherboard model number, and what hardware you want to change. Your readings are dead on; within +/- 5% is fine. Go to newegg.com and compare your dad's to some good examples from antec, corsair, ocz, seasonic, pc power and cooling, or enermax. None of these brands are cheap, so if you don't have the $$, I would leave the current power supply alone. 90% of desktops use atx ps; micro atx ps are significantly smaller, and you can tell just by looking at them.

Everest can't tell you if it's an ATX PSU or not. The side label on the PSU doesn't allows tell you either.

Your voltages appear in line ATX.

Try measuring it. ATX is 2.1" width, 3.4" height, and typically 5.5" depth (can be a bit different here).

So, I can find out whether a PSU is ATX or not, only by measuring his size?

The voltages are in line with ATX so that's the first clue. If the measurements correlate with the right size, you've hit a 2 for 2 test.

It looks like an ATX level system, if earlier than that the cpu core voltage would be much higher.

so why the system doesn't shut down completely by software?