Dell Vostro 2421 (Early 2013) - Manual (Page 13)

5. Remove the screw that secures the hard-drive caddy to the hard drive and remove it.
Installing the Hard-Drive Assembly
1. Slide the hard-drive assembly in its slot in the computer.
2. Tighten the screw to secure the hard-drive assembly to the computer.
3. Install:
a) memory module
b) access panel
c) battery
4. Follow the procedures in After Working Inside Your Computer .
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