Dell Alienware 17 R2 (Early 2015) - Manual (Page 23)

2 Slide the memory module firmly into the slot at an angle and press the
memory module down until it clicks into place.
NOTE: If you do not hear the click, remove the memory module and
reinstall it.
1 securing clips (2) 2 memory module
3 memory-module slot 4 notch
5 tab
Post-requisites
Replace the base panel .
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