2GB (1x2GB) Memory RAM 4 HP/Compaq Business Notebook nc6320, NC6400 Series A38 | eBay
HP Compaq nc6400 RAM Replacement - iFixit Repair Guide
HP Compaq nc6400 RAM Replacement - iFixit Repair Guide
2GB RAM Memory for Compaq HP Business Notebooks Business Notebook nc6400 Black Diamond Memory Module DDR2 SO-DIMM 200pin PC2-5300 667MHz Upgrade - Walmart.com
Removing keyboard and memory on HP Compaq nc6400 – Inside my laptop