It's common practice for the AGP (video card) slot to share its IRQ with the first PCI slot (arrowed). However, many AGP video cards don't like sharing an IRQ, so it's standard practice to leave the first PCI slot empty.

Actually, we tore out quite a bit of our own hair recently, battling instability in our new 1GHz Athlon PC. And although this article describes how we solved the problems, the basic approach described here applies to lots of other PCs as well.

That’s because there’s nothing unique about our hardware. Lots of motherboards use the Via chipset, while video cards based on the nVidia GeForce2 and TNT chips are commonplace. And of course, lots of PCs are fitted with sound cards, network cards and other devices.

So although your particular machine mightn’t exactly match ours, a lot of the advice given here still applies.

Our problems with our new PC really started when we decided to convert it for use as a desktop publishing machine. There were several things we had to do to: (1) convert the operating system to Windows NT; (2) install a 250MB ZIP drive; and (3) install a network card so that the new machine could be plugged into the SILICON CHIP network.

We cheated when it came to the Windows NT conversion by using Power Quest’s "Drive Image" to clone the installation from my old machine (the old machine was later converted to Windows Me). Before doing that though, we changed over to a standard VGA driver so that there would be no problems with the new video card. The 250MB ZIP drive was also pinched from the old machine and slaved with the DVD-ROM drive on the primary IDE port.

Did it work? Umm, no – it wouldn’t boot initially because it couldn’t find the drive (no driver for the on-board Promise Ultra ATA100 controller, you see). That was solved by temporarily transferring the hard drive to one of the "normal" IDE ports. This then allowed us to install the Promise driver from the motherboard CD-ROM, before swapping the drive back to the Primary Ultra ATA100 IDE port.

You don’t have to do this with a new NT install, by the way. You just connect the hard disk to the primary Ultra ATA100 port from the beginning and install the "SCSI" driver when prompted to do so during the installation procedure (Windows NT labels all disk drives as SCSI devices).

Next, the Via 4-In-1 drivers were installed, followed by the video card driver. These all went without a hitch, so the machine was powered down and the network card installed in the first PCI slot (ie, the slot adjacent to the video card AGP slot).

Initially, the network card wasn’t recognised, despite being exactly the same as in the old machine – that would make things too easy, wouldn’t it? This problem was solved by deleting and reinstalling the driver. The network then came up OK after we had re-entered the network settings and it appeared to be all systems go.