Can you test this with a Live Linux CD/DVD. If the system still crashes in Linux, its probably a buggy BIOS or a hardware incompatibility with your WiFi card. If it doesn't then it might be a bug in the Windows 98 driver.

hmm, that's a good point of idea, I'm gonna test it on a ubuntu 10 live cd and another puppy Linux live cd (and if it Works, the Windows xp live cd)

I have an athlon 1.3 ghz cpu an a Abit KT7 board.

And when cpu2pci write buffer is enabled the system freezes when i start using the bt848/878 video card.
For example virtualdub, dscaler, or any other tv software which uses overlay.

I have to disable cpu2pci write buffer, cpu pci concurency (or something similar called) , and pci master 0 ws.

Then the system runs stable.

ubuntu didnt worked (boot) neither the xp.
but puppy Linux did, the wifi was detected but it wasn't connecting, so idk if it's the driver itself or another thing.
I wish there was a generic wifi tool for 98 like xp (not requiring an external tool to connect to the wifi)

When you say neither Ubuntu nor XP worked, do you mean they did not boot or simply that they did not detect the WiFi card? In any case you could just dual boot to a small distro or XP (I.E actually install it) and then use a wired connection temporarily to get the WiFi drivers.
Also, I'd think twice before blaming the utility itself. This seems to be a lower level issue.

I mean they didn't boot (Ubuntu actually showed a background screen but after some time it entered in a black screen and didn't went out

So, I finished to install the Windows XP on this machine, and guess what.
The system was working actually fine, but it froze after some minutes that I installed the drivers...

Abit KT7's are notorious for Bulging capacitors. I have replaced all of them on mine.
If they are bulged on Your motherboard then that will almost certainly be the cause of Your problems.
Any bios performance setting would add to instability.

The system worked just fine with another wifi pci board, and also with an ethernet board, but not with this pci wifi board, idk if a bad capacitor would not work just with a specific board

There is a possibility that the WiFi chip itself has a hardware bug that causes the crash with PCI write buffer. Honestly, I'd ditch the WiFi card, grab an old DD-WRT or OpenWRT compatible router and make it act like a WiFi client. Then you can just connect the machine to the router thorugh a cable and it will be part of the wireless network.

ibm5155 wrote:

The system worked just fine with another wifi pci board, and also with an ethernet board, but not with this pci wifi board, idk if a bad capacitor would not work just with a specific board

I would check the capacitors anyway. You might also be lucky and have got a board that had good quality capacitors fitted.