I know we give up the right to assign IRQs once we install XP as ACPI-enabled. But in case someone has come with with hack, please do share.
And no, manually assigning IRQ at BIOS doesn’t work. At least it didn’t work for me.
Why the need to reassign IRQ? Well, apparently NVIDIA’s driver can’t handle shared IRQ line, which boggles my mind considering they are a well respected company. Updating the driver from their website didn’t help.
Re: IRQ assignment on ACPI enabled XP Machines
U need to change the settings from ACPI-enabled to standard pc. This is how you do it:
In Device Manager, expand "Computer" and right click the expanded entry. Select Update Driver, then choose "Install from a list or Specific Location (Advanced)", click Next. Select "Don't Search, I will choose the driver to install.", click Next. If Standard PC is shown in the list, choose it, otherwise uncheck Show compatible hardware, then select Standard PC from the list. Click Next. And you're done
Re: IRQ assignment on ACPI enabled XP Machines
Tofi Bhai, when you 'uncheck show compatible hardware' there is no Standard PC in the list.
The only way I know of is to reinstall XP and disable ACPI all together
Re: IRQ assignment on ACPI enabled XP Machines
I checked 3 computers and they all gave me the option. What brand is your's? I think you may have to rebuild it if you can't get that option.
Re: IRQ assignment on ACPI enabled XP Machines
self built 
screw brand names.
Re: IRQ assignment on ACPI enabled XP Machines
Why screw when you can nail :)
Re: IRQ assignment on ACPI enabled XP Machines
^^ Reminded me of satisfaction by benny benassi, cant you guys just keep the X out of comp chat for a while...:Mal1k thinking:...fk NOOOOOOOOO
Re: IRQ assignment on ACPI enabled XP Machines
As I know it there is no hack to install Standard PC image once you have installed XP as ACPI enabled image. The only way is to reinstall XP.
However, that being said, it is rarely the problem of ACPI which causes the hardware not to work. In fact, standard PC image will give you more trouble than not. Which NVidia card are you talking about? I had a similar situation sometime back where I tried to install a unresponsive card where the card manufacturer mentioned in their manual that card will not work if it installs under a cascaded IRQ. Whatever I did XP wanted to assign a cascaded IRQ to it. So I reinstalled the XP as Standard PC image and manually assigned the IRQ and guess what, it still did not work. Later I discovered that the problem was with the card itself - a hardware problem. So if possible, try another of the same type of card, install the drivers and see it works. Also many times, moving card to a different slot will work; try to install the card in the slot closest to the PCI-X/AGP slot.
Re: IRQ assignment on ACPI enabled XP Machines
WitchDr, its GeForce4 MX Integrated GPU.
I tried later drivers from NIVIDIA for this card, still didn't help. Most of the latest ones (driver, by checking their INF file) do no support this card anymore.
I switched the card which had a problem with this NIVIDIA card to another slot and the problem went away as Windows reassigned the IRQ. I know this is just pure luck.
Re: IRQ assignment on ACPI enabled XP Machines
Yes. Most of the times just moving the card to a different slot will make the card work. Good to know that you have an operation PC now.