Dell Dimension 3100C Owner's Manual page 63

NOTE:
Memory purchased from Dell is covered under your computer warranty.
NOTICE:
If you remove your original memory modules from the computer during a memory upgrade, keep them
separate from any new modules that you may have, even if you purchased the new modules from Dell. If possible,
do not pair an original memory module with a new memory module. Otherwise, your computer may not start
properly.
1
2
matched pair of memory
modules in DIMM
connectors 1 and 2
Removing and Installing Parts
63