do i need another operating system?

[nunbaggi]

Can i install freenas without another operating system (windows)??

 

[ben]

You need something to make the install CD or boot USB, but that's it. However, FreeNAS is not meant to replace an operating system, just to make managing external storage over a network easier - you're expected to have a desktop or laptop (or more) which FreeNAS shares files with.