8GB 4X2GB Dell OptiPlex 745 DDR2 PC2-5300 Memory at Amazon.com
OptiPlex 745 Ultra Small Form Factor (USFF) Removal Guide for the Memory, Hard Drive and System Fan | Dell US
FULenQnu Technology 4GB kit (2GBx2) Upgrade for a Dell OptiPlex 745 Series (Desktop Mini-Tower and Small Form Factor) System (DDR2 PC2-6400 Non-ECC) - Walmart.com
Refurbished: Dell Optiplex 745 Mini Tower Pentium D Dual Core, 3.4 Ghz, 500 Gb Hard Drive, 4 Gb Ram, Windows 7 Home Premium - Newegg.com
OFFTEK 2GB Replacement Memory RAM Upgrade for Dell OptiPlex 745 (Desktop MiniTower and Small Form Factor) (DDR2-5300 - Non-ECC) Desktop Memory at Amazon.com