Lenovo ThinkCentre A58e 3425 User Manual page 19

Figure 5 shows the locations of the drive bays in your computer.
Figure 5. Drive bay locations
1 Bay 1 - Optical drive bay (with an optical drive installed)
2 Bay 2 - Secondary SATA hard disk drive bay
3 Bay 3 - Primary SATA hard disk drive bay (with a 3.5-inch SATA hard disk drive
installed)
Chapter 1. Product overview
11