As Andy mentioned you can create and delete partitions during the OS setup, but if you already have all the software installed and just need to partition an extra drive you're popping into your system then go to "Administrative Tools" in the control panel. If you're using the WinXP category view layout, then click on the "Perfomance and Maintainence" option in the control panel first to see the Administrative Tools option. Under Administrative Tools, select the Computer Management option and then select Disk Management in the new window. In the bottom frame of the window you'll see all your drives and their partition information. Right click on one and you can create, delete, etc.