If you stick a new disc in you may have to Format it, but if use quick format on a new disc it takes seconds, if you do a full format it could take quite awhile depending on size of new disc a 1 TB full format could run over 4 hours for a full format. But after you do the quick format on a new disc just boot up your Macrium restore disc and restore the image to a new Hard drive if you ever needed to do that. Remember your CD/DVD must be the first in the boot priority in the BIOS and you had to put in a new HD you might have to make a bios change on which drive the Bios HD the Bios looks for for boot up. Do not worry about that at this point since you are not putting in a new Hard Drive