NeweggBusiness - DELL OptiPlex GX520 Desktop PC Pentium 4 3.0GHz 2GB 160GB HDD Capacity Windows XP Professional 32-bit 3 Years Warranty for School and Colleges only (Verification Required)
Dell optiplex gx520 GPU upgrade - Dell Community
4GB [2x2GB] DDR2-533 (PC2-4200) RAM Memory Upgrade Kit for The Dell Optiplex GX520 Desktop (Genuine A-Tech Brand) at Amazon.com