Does setting RAID disks require all disks to be in RAID?

Question

I am interested in running a PC this way, 1 C: main OS drive and 2 2TB +2TB in RAID 0

Windows is already installed and I wanted to add the disks later. Do I have to reformat C: to RAID to be able to have it working with the RAID 0 disks. I just want to format the secondary D: to RAID 0 disks and add it to the system without reinstalling Windows. C: will not use more than one drive so it seems useless to have to make it RAID.

Answer 1

No, you don't need to reformat C: and add it to a RAID.

Simply add your new 2 disks to a RAID 0, and they will show up as one drive (D: for example). That's mostly it.

Answer 2

If you have a Pro or Enterprise edition of Windows 8, 8.1, or 10, then you may use a more advanced RAID technology that is called Storage Spaces, without changing anything with disk C:.

See this answer for more information.