Dell OptiPlex 390 (Mid 2011) - Manual (Page 23)

9. Release the screws that secure the 2.5 inch hard drive to the underside of
the hard drive bracket.
Installing The Hard Drive
1. Tighten the screws to secure the 2.5 inch hard drive(s) to the hard-drive
bracket.
2. Flex the hard-drive bracket and then insert the single 3.5 inch hard drive or
the two 2.5 inch hard drives into the bracket.
3. Press the hard-drive bracket latch towards the hard drive and insert it into
the chassis.
4. Connect the data cable and power cable to the back of the hard drive(s).
5. Install the
cover .
6. Follow the procedures in After Working Inside Your Computer .
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