I have no knowledge of installing disks so treat my suggestion with caution, but if you are confident enough to remove one of the RAID 1 disks from its internal enclosure, why not do that, pop it into an external USB enclosure and connect it up to the second workstation that way through a USB port?
You remove any BIOS or SATA controller difficulties that way.
If that is possible, you will still likely need to "Take Ownership" of all the folders and files on that disk and the Microsoft article below explains that;
Does that help?
Thanks to a fast moving electrical storm my primary workstation failed. Operating system XP Pro, 2-250 GB SATA HDD in a RAID 1. I have a second similar workstation same make newer model, SP Pro, 2-160 GB SATA HDD in RAID 1. Can I install one of the 250 GB HDD in the working workstation as disk 3 and copy the data over? Will the BIOS dispute the RAID? Yah I know back-up but I am looking for a solution for now. I am in the process of networking my 3 computers with backup NAS.