Well, when you raid a set of drives, particularly with a raid "solution" that depends on drivers in the OS to do a lot of the work, you petty much accept that you are not going to be able to see these drives with other OSs, with many recovery programs, and the like. Knoppix should not write to your disk. But to be safe, why risk it? You have 2 SATA drives. The connect by very small easy to disconnect plugs attached to your motherboard. Since you say you want to try Knoppix on CD but already know that it isn't going to even read that raid set of drives, why not just unplug the drives and try knoppix, then plug them back when you are done? (hint: it might be helpful to note which plug goes where when unplugging them, they may look a lot alike and raid will not get the joke if the plugs are reversed) Otherwise you can wait for someone else to come along and reassure you that nothing will go wrong when you boot with the drives still attached, but in the end it's you who take the risk and you who can do something to protect yourself.