1GB Kit [2x 512MB] RAM Memory Upgrade for the Sony VAIO PCV-RS422X Desktop Systems (DDR-333, PC2700) Guaranteed Compatible for the Sony VAIO PCV-RS422X Speed up your system with up to 2GB of memory! Lifetime Replacement Warranty! Will ship the same day when ordered at or before 4pm EST! All others ship next day! Fully-staffed call center to help with installation or inquiries! Call 866-335-1355 with questions or for help!