The n Series is a Dell product line that does not ship with a pre-installed version of Microsoft Windows. Apparently prohibited from shipping computers without an operating system by an existing licensing agreement with Microsoft, Dell instead ships these systems with either the open-source FreeDOS operating system or the Ubuntu Linux distribution.

A result of OEM licensing with Microsoft, Dell is also prohibited from advertising these computers.^{[citation needed]} Customers must request them specifically or search for them on Dell's website. The company has come under fire for making the FreeDOS-powered machines no cheaper and more difficult to purchase than identical systems running Windows^[1].

Dell also offers various Precision Workstations with Red Hat Enterprise Linux pre-installed.