Nothing will need to be switched other than most likely RAM. The majority of components share common properties.

W.

Well, that really depends on what the motherboard has for onboard peripherals. If it has onboard AGP(video) you will need a new video card. Either way you most likely will need a new video card and memory. The Optical drives(CDROM or CDR/W) and hard drives can be kept. Lose the IDE cables and get yourself ATA 100 cables as well.
If it's an ATX tower system then you will be just fine but check into whether it's a baby tower or mid tower. If Baby look forward to getting a new case. One other thing, power supply!!! P4 systems need a different PSU than the celeron systems do.
I'm sure at this point it seems like it's not worth it but it could be in the long run.
Run some q's by us and we'll help you through it
Opus :D

All right!

My case is what I assume would be called a baby tower: it's an HP Pavillion 6736, currently equipped with a Celeron 667 MHz, 384 Mb RAM (PC100) running Windows ME. As far as I can tell, the sound and video "cards" are integrated and it's got Intel graphics accellerators. Video is not that big of an issue for me - as long as I can see what I'm working on I'm fine. :)

I have recently purchased a MOTU 1224 interface and it goes without saying I'm having some difficulties (gotta start somewhere.... :D

Your benevolent expertise is greatly appreciated.

Also (forgot to add)

What is the difference between IDE and ATA 100 cable?

If I gut my old 386 and use the case for a new P4 motherboard (not a tower but the other style...uh...flat) would a P4 power supply fit in the same compartment that the 386 power supply fit into?

Are all P4 power supplies the same size?

Do you have a line on where a fine urban Canadian could pick up relatively cheap, high-end computer parts?

So many questions...Thanks for your patience. :tu:

Along these lines,

I was reading elswhere on this site about the stability Windows 2000 provides audio applications compared to the 9X series. How much further does XP take this? Would I have to get XP Professional in order to retain that same stability or does XP Home cover that ground?

In a nutshell, what is the Windows OS that provides the most positives for audio applications? (or the least negatives)

Well, bad news for ya bub! That case ain't going to work at all! It's not going to house the newer motherboards at all...slots won't line up, ports won't line up..power supply will not fit either!
Your monitor will work regardless but you will need a new case, mainboard, cpu, memory, video card, hard drives...you can keep your floppy and CDROM though :roll:
You are better off buying a new system in the long run. Yes, Win2k or Xp is a hell of a lot better than 95 or 98SE...When and if you get a new system I highly gaurantee you will be ditching the Crystal audio card as that is most likely an ISA slot based audio card....
Sorry this isn't the news you probably wanted to hear but it's the plain out truth!
Opus

For what you seem to want to do, it would be best to build a whole new tower. If you try "Frankensteining" your current tower, you'll have nothing but problems. Every component in your current tower (except the floppy drive ...lol) is FAR behind today's technology. However, just because you read about guys on RO spending $1500-2000 to build a tower doesn't mean that you HAVE to do that! You can build a KICK ASS, complete DAW tower for about $700-800. If you would like me to list the components to do that, just ask. ;)

That would be great! The only concern I have would be the conversion of currency. As I'm sure you're aware, the Canadian Peso :D