4GB 2X2GB Memory RAM for Dell OptiPlex 755 Mini Tower 240pin PC2-5300 667MHz DDR2 DIMM Black Diamond Memory Module Upgrade - Newegg.com
Optiplex 755 USFF cpu and ram upgrade - Dell Community
Upgrading old Dell Optiplex 755 for light gaming - New Builds and Planning - Linus Tech Tips
1GB RAM Memory Upgrade for the Dell Optiplex 755 Desktop | eBay
How to upgrade a DELL OptiPlex 755 USFF PC - YouTube
CMS 4GB (2X2GB) DDR2 6400 800MHZ Non ECC DIMM Memory Ram Upgrade Compatible with Dell® Optiplex 755 Dt/Mt/Sff - A90 at Amazon.com
Optiplex 755 766 - YouTube
OFFTEK 2GB Replacement Memory RAM Upgrade for Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor) (DDR2-6400 - Non-ECC) Desktop Memory at Amazon.com
Terri's Random Ramblings » Dell Optiplex 755 Upgrade Project