Maybe I missed it but Disk 2 is new information. You need to be careful and it is generally not a good idea to have 2 "cloned" disks connected at the same time.
You can try the following:
1) disconnect disk 2 and make sure your PC still boots
2) Reassign a new volume letter to disk 1 (D: ) ....say G
4) go back into "change settings" and see what happens