Windows

For many reasons (performance, reliability, recovery, etc), use hardware based RAID. Since you already have invested in four 20GB disks, I would continue investing in a hardware RAID Controller. Once you setup the RAID controller, decide how to present the disk(s) to the OS (Win2k). You can present 1 disk to Win2k and use Win2k to carve it up, or present multiple disks to NT. These will appear as physical disks in MMC-Disk Admin. Treat them as you would treat physical disks.

I would present multiple disks to the OS. You will have ~60G to present. Use 4 or 8 GB for C: (system drive). I would further split up Applications and Logs (D:, E:). Also, you may want to split out User data (F:, etc). This will give you flexbility, andthe redundancy for which you purchased the drives.