How many network adapters does a standalone PC need?

I know nothing at all about network adapters apart from what I have learned in the past hour's research. Apologies if I've posted on the wrong forum.

I have built a PC: Asus A8R32-MVP deluxe motherboard and radeon 1900xtx graphics card etc. It's a high spec rig but I have had IRQ and other conflicts which have been largely solved by uninstalling the audigy 2 nx sound card (temporarily).

Looking in device manager I have 4 network adapters:
1) 1394 net adapter;
2) Marvell Yukon 88E8001/8003/8010PCI gigabit ethernet controller
3)Marvell Yukon 88E8053 pcie gigabit ethernet controller

4) Speed touch USB ADSL ppp

I have one pc and do not intend to do any home networking -it's just the one PC. I know 4) is my internet connection which I know I need.

Number 3 is sharing an IRQ with my graphics card which may explain some of the IRQ errors.

My questions are:

1) Do i need the first three adapters;
2) If not can I safely disable them.

I want to disable them to reduce the chance of future IRQ conflicts.

Looking at the events viewer, some of the conflicts (see below) have mentioned a 'server' (which I assume is something to do with networking) and a device trying to communicate with a server (which I assume does not exist). The device trying to communicate with the non existent server is, I have assumed, one of the adapters.

"DCOM got error the service database is locked attempting to start the server SENS with arguments in order to run the server...."

Sorry if this is garbled...

Thanks.

In which case I'll disable all three.

I have no firewire devices and LAN is not required.

On of the ethernet devices is sharing a IRQ with my card which may explain conflicts I've been getting.

Thanks for your time.

baz