The PowerVault 725N can store up to 480Gbytes of data and is aimed at small businesses and workgroups within larger companies.
The system is at the low end of the company's NAS line, which also includes the PowerVault 770N and 775N systems that started shipping earlier this year, said Marc Padovani, product manager for Dell's enterprise systems group.
Dell competes against IBM, Network Appliance, and Hewlett-Packard in the lucrative NAS market. These types of storage systems plug into Ethernet networks and offer customers more flexible ways of moving data around their companies than direct attached storage systems.
The PowerVault 725N runs on Pentium 4 processors from Intel and Microsoft's Windows Advanced Server (SAK) server appliance kit operating system. Pricing for the system starts at $1,799 (£1,133).
The higher-end PowerVault 775N, available since August, and the 770N, available since October, use more powerful Xeon chips.
Dell also said it was looking to offer NAS systems next year that support Internet Small Computer System Interface (iSCSI), one of the storage industry's most talked about technologies.
The iSCSI protocol helps bridge a gap between Ethernet-based NAS networks and storage area networks (SANs) that use Fibre Channel connections.