Dell Inspiron 1428 (Late 2009) - Manual (Page 31)

Memory Module(s) 31
6 Remove the memory module from the memory-module connector.
Replacing the Memory Module(s)
1 Follow the procedures in "Before You Begin" on page 9.
2 Align the notch in the memory module with the tab in the memory
module connector.
3 Slide the memory module firmly into the slot at a 45-degree angle, and
press the memory module down until it clicks into place. If you do not hear
the click, remove the memory module and reinstall it.
NOTE: If the memory module is not installed properly, the computer may not
boot.
1 memory-module connector 2 memory module
3 securing clips (2)
1
2
3