How does the time machine icon appear on HDMcIntosh drive in a Mac
Ask to look at an elderly friend's Mac because of trouble with Time Machine. Much to my surprise he had two drives with Time Machine icon - an external, but also his main Mac drive??? I got the external reset and reinitiated as Time Machine, leaving the main drive alone. Now there is a difficulty with Time Machine over a "Untitled" (file?, drive?) on this main drive.
I suspect that he originally designated his main drive as his Time Machine. I hesitate to try to delete or change too much on his main drive in that it might be wiped out? I also, suspect, however that the Time Machine is actually continuing to back up his main drive in the main drive.
Any suggestions would be most helpful.