The Ethernet Disk stands out from the rest of LaCie's NAS units in that it contains an embedded version of Windows XP that oversees all backup, storage, and sharing activities. With Active Directory support, the Ethernet Disk can manage networks of up to 100 users, while up to 25 can access the NAS at once. Four USB ports allow for expanded storage, or additional backup. The device is compatible with Windows, Mac, Linux, and Unix, and works with Time Machine on Macs. Backup software is included for Macs and PCs.