Solved: Issue with installing more RAM dell optiplex 390 - Dell Community
Solved: OptiPlex 760 memory upgrade? [small form factor] - Dell Community
Dell Optiplex 755 Desktop Core 2 Quad (Q6600) Ram
Restored Dell Optiplex 755 Desktop PC with Intel Core 2 Quad Processor, 4GB Memory, 1TB Hard Drive and Windows 10 Pro (Monitor Not Included) (Refurbished) - Walmart.com
A-Tech 8GB (4X 2GB) Max Memory RAM Kit for Dell OptiPlex 755, 745, 740, (MT, DT, SFF) - DDR2 667MHz PC2-5300 Non-ECC DIMM Upgrade at Amazon.com
4GB [2x2GB] DDR2-667 (PC2-5300) RAM Memory Upgrade Kit for The Dell Optiplex 755 Desktop (Genuine A-Tech Brand) at Amazon.com