I'm trying to free up an IRQ so my card doesn't share with my modem (which is currently the case). I was told that disabling my serial ports in the BIOS would possibly free up some IRQ settings.

I realize these are the same as COM ports, but I'm not exactly sure what they DO. I've searched around a bit and seen posts where people say they no longer USE their serial ports so they disabled them, but have been unable to find out WHY someone would no longer need to use these ports.

How do I know if I can safely disable my serial ports?

If you don't use an external modem, or have a mouse made in the past 5 years, or if you use an IR port on your computer, or don't have some other old piece of equipment, then you don't need a serial port.  Its going the way of the ISA expansion slot.  Items like USB and broadband going to a NIC has eliminated the need for a serial port.

So, unless you are using it for some reason, you don't really need it.  Me, personally, I don't have an IRQ problem, so I haven't gotten around to disabling them.

Just ask yourself.  Is anything plugged into them?  Do I use an IR port on my computer, if so equiped?  If you answered no, then you'll have no problems.

Yep, as long as you aren't using them, definitely disable them.

Also most BIOS's have a thing about "Modem use IRQ 3" that may force a your modem onto 3 if lets say it was trying to share 5 or something with other hardware.