WE are thinking about upgrading from 3.7 to 4.0. We have heard some systems crash during the upgrade process. Our BCM is equipped with a mirror drive, my question is can we take out the Mirror Master and replace it with a blank hard drive and make a mirror of the current system? If yes, will it do it automatically after it boots up? What kind of hard drive you you have to have, does it have to be identical to the ones currently in there? It currently has a Maxtor 2F020L0 in it. Thanks!