Morning all ive not had my iMac that long (about 3 weeks) i clicked on the time machine icon for the first time this morning.i get 3 options Time machine not configured is grey when i go to the last option (open time machine preferences) i see time machine is turned off. Should this be turned on? what could happen if this is not turned on? i hope you can pardon my lack of computer Know how. thanks again Steve.