Converting RAID 0 to Basic

I'm not sure if this belongs on this forum, or on the Hardware forum. My question relates to both software and hardware.
I have a HP Media Center 8330f computer. Standard configuration except I have updated from Vista to Windows 8.1. Computer shows single 640 GB hard drive, but there are two 320 GB drives installed. Lots of reading on the internet leads me to believe that the motherboard comes with Raid 0 installed at the factory, and it cannot be uninstalled except at the factory. If anyone here can confirm this, it would be appreciated.
I also understand that only SATA 0 and SATA 1 are part of the RAID 0 config. It has 4 SATA ports, so I gather SATA 2 and SATA 3 would work as basic drives.
One of my hard drives is apparently failing, which leads to this post.
Several questions.
1. If I do not use SATA 0 or SATA 1, but load my operating system onto a disk on SATA 2, would the system ignore RAID and just act like a normal basic computer?
2. Can I ghost everything on the SATA 0 and SATA 1 RAID configured disks onto a new disk on SATA 2 that is basic configured? I would want to include the Operating System partitions. I would also like the Windows 8.1, which is legal and fully activated, to be recognized on the new hard disk. Not sure if this would generate an issue with Microsoft or not.
3. The two disks total 640 Gb. I have two available new disks, one at 500 GB and one at 1 TB. Would either of them work? Would Ghost have a problem since the total disk sizes would be different? Would Ghost even work at all?
4. If SATA 0 and SATA 1 are empty, can I assume the computer would automatically look to SATA 2 for an operating system to boot up?
5. Can anyone explain how the disk controller could be setup? Does it have two controllers, one for RAID on SATA 0 and SATA 1 and another one for SATA 2 and SATA 3? I want to make sure that if I added another disk to SATA 3, that the system would not convert back to RAID 0 across SATA 2 and SATA 3.
6. I read that some of these came with RAID 0, and some with RAID 1 and some with the basic controller enabled. How do you tell? There is no RAID configuration utility. I have tried to access one through all the methods I could find and none of them work. Reinforced what I was told that it was strictly factory enabled or disabled.
7. One side note about Windows 8.1. When one of the disks first glitched, the computer went into Safe Mode. Would not get out, no matter how I tried. I had originally installed Windows 8, and then upgraded to 8.1. I had the Windows 8 installation disks, but not disks for 8.1. The system would not accept the Windows 8 disks for recovery. Finally went to the Microsoft website and downloaded their ISO for Windows 8.1, burned it to a disk and used it to recover. Worked fine, except that it would not replace files, like sfc /scannow, which is what I was used to. Instead it 'refreshed" Windows 8.1 which means that it wiped out every program I had installed on the computer except for those Apps that I had purchased or downloaded directly from the Microsoft Store. That was a real bummer.
Thanks for any help you can give.
David