I'm wondering if anyone has done what I'm thinking of doing - either succesfully or unsuccesfully.

This is my current setup:
Asus P5K-Deluxe with ICHR9 running Vista
2x500gb drives configured as one 450gb RAID 1 for data and one 100gb RAID 0 for the OS via Matrix Storge Manager.

Additional resources:
500gb external USB drive (which could hold the data I have on the two main partitions, barely)

I've run out of space on my primary partitions. I want to migrate from my two Matrix arrays to either
A - one big, regular RAID 5 or
B - a 100gb Matrix RAID 0 for Vista and apps + a bigger Matrix RAID 5 for the data

For A, I think I could take these steps:
1 - make a new 1tb RAID 0 array out of the new hard drives
2 - copy everything to the new array, then boot from the new array
3 - Use the Intel storage manager utility to migrate from the new RAID 0 to a big, traditional RAID 5 with all four drives (since RAID 0 to 5 migration is supported by the matric manager software).

For B, I think I could do this:
1 - image the boot array to the external 500gb drive (that's the 100gb matrix RAID 0 volume)
2 - copy the music and whatnot to the external drive, too (or image it, too - I don't think it matters)
3 - create a new Matrix RAID 0 with 25gb from all four drives and a Matrix RAID 5 for the rest.
4 - restore the original two drive matrix RAID 0 boot image to the new four drive matrix RAID 0

Are my steps wrong? Have I overlooked something?
Can I restore images from a two drive array to a four drive array? Is there anything special about the fact that the volumes are matrix?
Which do you think is better for speed, reliability, and simplicity?
Has anyone actually done this with my hardware?
Is there any ghosting software that's cheap, easy to use for relative beginers, and reliable? I'm not a newbie but I'm not a wizard, either.

I know reformatting is always the very best way, but I'm worried about all my license keys and network settings. It's such a pain in the a**.

What new drives do you have?

All are WD Caviar SE16 WD5000AAKS

If I remember correctly, the ICH9R has 6 SATA ports. I think you may be able to plug in your 4 WD drives into 4 of the SATA ports and create a new array (All RAID 5, or RAID 0/RAID 5 matrix). Then, image the partitions from the old array onto the new array. Then remove the old array and set the new one to be the boot device.

If the Intel controller won't let you set up two arrays, or won't let you matrix the 2nd one, then image the two partitions you have to your external 500GB, then remove the old array, insert the 4 new WD drives, create the array how you want it, and image the partitions back.

For imaging, I recommend Acronis True Image or Symantec Ghost.

This whole thing worked like a charm. I decided to go from a two drive matrix RAID 0 + RAID 1 into a four drive matrix RAID 0 + RAID 5.

For the benefit of anyone who's nervous about screwing around with RAID arrays and re-imaging, here's exactly what I did. I imagine that this process will work for anyone with an Intel ICH9R chip. I've heard that earlier ICHxR's are darn near the same thing, too.

I imaged my original matrix RAID 0 boot volume to my USB hard drive. I used Acronis' 15 day free trial of TruImage Home. That's excellent software, btw - its very slick and fairly straightforward. I know there are other programs that work fine, too, but Acronis worked for me. I might even bite the bullet and pay them for the software to use as a backup tool because it worked really nicely. The imaging process took two hours for 50gb to go from my internal matrix RAID 0 to my external USB drive, which is quite speedy considering what it's doing but it's not instant, so be patient.
Then I copied my music and videos from my old matrix RAID 1 partition to the same external drive, too. I double checked to make sure that all my data was on the external drive and the image file was on there, too.
Then I made an Acronis boot CD. The only option to choose is whether you want USB and network support or not - clearly, I checked that box since I need USB support to get my image.
I rebooted and hit DEL to enter the BIOS setup so that I could tell the computer to boot from the CD drive instead of the RAID 0 partition.
Then I booted from that CD just to make sure that it worked. It loaded right up into a primitive looking pre-Windows Acronis screen. It's ugly but it's pretty darn cool that its even possible. I just ran the TruImage program off the boot CD and verified that it found the image I made of my old boot volume. It did, no trouble. So I figured everything looked good and it was time to blow everything away and see if this works.
I rebooted again and hit "ctrl-i" at the Intel Matrix portion of the POST process. Up popped the Intel manager. Like SomeJoe7777 said, I first told it to kill off my old RAID partitions. That part goes instantly - viola - all your data is gone. Then I told it I wanted a new RAID 0 and I wanted it to be 160gb (40gb off each 500gb drive). That goes instantly, too. Then I told it I wanted a RAID 5 with the rest of the space, and viola - the RAID was set up, as far as the BIOS and motherboard was concerned.
I rebooted and the Acronis boot CD fired up. This was the only halfway tricky step - it's just not quite clear what to do but some minor fiddling figured it out. I told it to restore my image to the new C: drive. TruImage popped up a graphic representation of the image file and at that point, I had to figure out that what I was supposed to do is drag the image to stretch it so it took up the whole 160gb of the new C: partition, since the image was taken of a smaller 100gb partition. I'm not sure what would happen if I didn't drag it out - maybe there would be extra unpartitioned space on the C: volume or something. That was the only halfway tricky part - Acronis had good instructions the rest of the way.
Anyway, I then told it to make the newly imaged partition "active" because the well written instructions indicated that's what you do if you want the imaged partition to be the one you boot from.
So I told it to go and it took another two hours.
I came back, rebooted, and got a scary message about needing to put a boot disc in.
Then I remembered to go and change my BIOS settings back so that the motherboard would know to boot from the hard drive again - whew.
I did that, and VIOLA! I'm up and going with a 160gb RAID 0 partition and zero side effects.

I can't use my RAID 5 yet because it needs to be initialized. That part is taking FOREVER - 7 hours for 1.3tb - but RAID 5 always needs to be initialized so that's fine. In the meantime, I can get to my music and everything via the backup copies on the USB drive so its all good.