Check data entry for a 1099-MISC (99M screen) on which C is selected in the For field. This data entry will create a Schedule C.
If the 1099-MISC is not needed, delete the 99M screen. You may need to delete the 99M screen, recalculate the return, then delete the C screen to remove the schedule from view.
If it should be for a different schedule, change the FOR box selection, recalculate the return, and delete the C data entry screen.
If there is no 99M screen, delete screen C in data entry to eliminate the possibility of any data entered there inadvertently. Open screen C and press Ctrl+D on your keyboard to delete the screen (or right-click in a blank area of the C screen and select Delete Screen from the drop menu).