I assume what you mean by "Not recognized by Windows" is that you don' t see the drive in My Computer.
Go to Start>All Programs>Accesories>Administrative Tools>Computer Management
(on Win2K - right click My Computer, and Choose "Manage")
When this comes up, underneath "Storage" - choose "Disk Management"
Find your blank drive, and right click on it, and choose "New..."
I forget the symantics of this here, but essentially, you need to create a new logical partition.
Once this is done, you will see it in explorer.