Hi everyone!
I'm having this strange problem from a long time now, even with Kubuntu version 6.06 and other distros like suse and mandriva. My linux doesn't load unless I boot firstly to windoz and then restart and boot the linux. I tried everything but no luck (pci=bios,biosirq, noapic,noacpi,nolapic), untill I discovered that when my onboard Lan is disabled by the BIOS, linux will load, same thing when I disable the autostart option, of the network, from within kubuntu. When my net card is enabled I have to do all that tra-tra with win that I mentioned before, again and again.

Does anybody know what's going on? (Gigabyte sis965 chipset, onboard sis191 ethernet device).

I'm thinking of migrating completeley over to Kubuntu, but with this problem my hands are tied....no internet.

Quick suggestion: disable the onboard Lan in BIOS, then install another network card in a PCI slot. RTL8139 based cards are really cheap and work with everything.

I have had weird problems like this in the past that have been caused by IRQ conflicts with other devices, and sometimes bad BIOSes.

Last thing to do, (AND DANGEROUS!) is to check that you have the latest BIOS, and install new one if you don't. Most likely, because you have a Gigabyte board it has 2 Bios chips, in case one gets a bad write, so you are probably fairly safe.

Well, thanks for your quick suggestion combatowombat, I believe I'd read something similar a few days ago, perhaps even from your post, but I don't think this is a solution, it's trully radical. And if that's the case, irq's conflicting, howcome it works well with win? There must be an answer to that!

I must also say that I did actually flash my BIOS with the new version, a few days ago, nothing changed...

Your on-board ethernet needs the module sis190.
I read that some distros do not reliably detect your on-board ethernet, and therefore may not be loading the required module.
Maybe windows does something to the hardware that then makes it easier to detect.
Suggestion: Boot so it doesn't work. Do sudo lsmod | grep sis in a terminal.
Is the module sis190 loaded?
If not then load it: sudo modprobe sis190
Now try and bring your interface up.

Edit Sorry, just re-read your post: If it is not disabled, you cannot boot.
So, try this: Add the line sis190 to the file /etc/modules.
Re-enable the chip in the BIOS and reboot. It works?

Nope, that didn't work either...still freezes at boot.

Windows drivers are handled differently to Linux. They can often work with assigning an appropriate IRQ and memory space for the piece of hardware, which is why it will work with Linux after Windows has worked with it. Because Linux tends to just work with whatever is there and currently set, reading the hardware settings from the flash memory on the device.

Anyhow, after Googling, there are lots of people having problems with the SIS190 http://kerneltrap.org/node/4838.

I still recommend putting in another network card.

In the BIOS make sure IRQ is assigned by the BIOS. If it is set to OS, Linux will not assigned IRQ. In order for Linux to work correctly, IRQ have to be assigned by the BIOS. Though, I have seen some devices work by specifying noapic and sometimes noapci or apci=off

Well, what can I say, surely what combatwombat said explains the thing with windoz, and after googling by myself I believe that it doesn't matter which linux distro I install, the problem will always be there since the driver's always the same.

I'll give it a last shot, using the acpi=off that Electro suggested (I've used all the other but not that one)and if that doesn't work, I'll deactivate the lan support under linux for the time being, having no internet sucks though...