Update: I've seen that the fastest tested board is the 8400GS PCI requiring 20W. The FX5200 PCI I'm using seems to be around 25W at best. I wonder if the 30W Geforce 210 DDR3 PCI would risk the mainboard PCI bus or it is in the specifications.
I've found on another forum this info:

Depending on the present signal, the slot determines whether the expansion board had been inserted or not. After the expansion board is inserted, 2 pins namely PRSNT1# and PRSNT#2 determine how much peak power the PCI card is going to need:
PRSNT1 | PRSNT2 | Power allocated |
-----------------------------------------------
open open> 0Watts
open g> 15 Watts
g open> 25 Watts (max)
g g> 7.5 watts

g = ground.

It'd looks like the maximun power draw from the PCI bus should be 25W with the board I will use should ask for 30W I suppose. I wasn't expecting it. I wonder also how other faster cards like the GT610 or GT710 PCI can work in any PCI bus.

The 1998 PCI 2.2 specification requires PCI cards to limit themselves to 25W power drawn on all rails combined.
The specification does not require a motherboard to be able to deliver that current however. It leaves that to the manufacturer so wether the board is capable of supplying sufficient current is anyone's guess. 😅
Personally I wouldn't worry about my board. The board does not generate the voltages on the slot, it only stabilises them. I can't imagine the board manufacturer not designing their circuitry to support sufficient current for a single PCI card.
I also can't imagine the card drawing significantly more than a PCI card is allowed to because it wouldn't be PCI compliant anymore then. The German Wikipedia article also has the GF 210 rated at 21W power draw under 3D load. Nvidia's MGCP does not equal actual power drawn by the card plus card designs may vary in power draw.
If you're cautious you can try finding the transistors and checking wether their temperatures stay within specification during operation.👍

Doornkaat wrote on 2020-09-12, 08:57:

The 1998 PCI 2.2 specification requires PCI cards to limit themselves to 25W power drawn on all rails combined. The specificatio […]
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The 1998 PCI 2.2 specification requires PCI cards to limit themselves to 25W power drawn on all rails combined.
The specification does not require a motherboard to be able to deliver that current however. It leaves that to the manufacturer so wether the board is capable of supplying sufficient current is anyone's guess. 😅
Personally I wouldn't worry about my board. The board does not generate the voltages on the slot, it only stabilises them. I can't imagine the board manufacturer not designing their circuitry to support sufficient current for a single PCI card.
I also can't imagine the card drawing significantly more than a PCI card is allowed to because it wouldn't be PCI compliant anymore then. The German Wikipedia article also has the GF 210 rated at 21W power draw under 3D load. Nvidia's MGCP does not equal actual power drawn by the card plus card designs may vary in power draw.
If you're cautious you can try finding the transistors and checking wether their temperatures stay within specification during operation.👍

Thanks. It's not that I care so much of the mainboard but more of the retail boxed owned Win license connected to it and if it would fail without disconnecting from this config, I don't know the procedure to detach from the previous computer when it fails before installing it into a new one and I understand that it's faster to do that with the functional installation.
I bought a 210 DDR3 512MB cause it was the cheapeast more modern card I found for this bus even if I know how slow it still would be but anyway I should get some more compatibility with softwares anyway compared to the SGX545 iGPU I was using and the FX 5200 PCI I'm trying these days that consume a lot of power (I've a watt meter to the wall plug), generate lot of heat and it's slower than the iGPU if that's possible.
It probably came to my memory what happened with the early Geforce SDR cards on older AGP mainboards where the power drawn from the bus if I remember correctly was sometimes even higher than some mobo could handle.

I believe if you have the license key you can call Microsoft and they will remove the registration or transfer it to a new device etc.
There are tools to read out a product key stored in BIOS/UEFI iin case you lost the sticker.
Anyway I wouldn't worry about PCI power draw on a single card too much. The early AGP power fiasco was mostly due to Intel not really specifying maximum power draw in their AGP 1.0 specification. They just vaguely predicted an increase in power draw. Some manufacturers then designed their boards around power requirements of existing 1997/1998 cards. The PCI 2.2 spec is much more significant in regards to what currents are to expected.

Doornkaat wrote on 2020-09-12, 14:00:

I believe if you have the license key you can call Microsoft and they will remove the registration or transfer it to a new device etc.
There are tools to read out a product key stored in BIOS/UEFI iin case you lost the sticker.
Anyway I wouldn't worry about PCI power draw on a single card too much. The early AGP power fiasco was mostly due to Intel not really specifying maximum power draw in their AGP 1.0 specification. They just vaguely predicted an increase in power draw. Some manufacturers then designed their boards around power requirements of existing 1997/1998 cards. The PCI 2.2 spec is much more significant in regards to what currents are to expected.

I never had to follow the config license change procedure and I was wondering how it works. I got the retail genuine box with the double dvd version, sticker and all, bought some years ago and I installed it into this mini-itx board cause it was the only brand new mobo I got instead of all the other too much old mainboards where the fastest were for the Core2 Duo/Quad.
From a speed point of view this config is doing more than expected and the Geforce 210 should help a bit on the GUI/3D side even if I've to say the famous SGX545 can work into a 32bit installation/32bit drivers and with all the features. But the 3D side is quite complicated as already said in various threads. So without going for an expensive GT610 or GT710 PCI that would still be cpu limited or bus limited, I went for the lowest end choice.
Too bad I've to keep the 32bit installation because if I reinstall the 64bit with the new vga I've to reinstall who knows many gigabytes of win updates.. I don't think there'd be much difference beside the full 4GB of ram reading.