Software Raid 1 in XP

I've collected a whole bunch of crap as time goes -- about 160GB, and it's all on a 200GB drive. I just got another 200GB drive. I've searched all over the places, but couldn't find anything on how to set up software Raid 1 in XP. Many people claim it can be done on a non-system drive in XP.

I am not sure if anyone here knows anything about it or has done it before.

I do have a Silicon Image Raid controller that supports Raid 1 and 0, but according to its manual, its max addressable space for Raid is 144GB.

I have 4 drives now in my system. OS runs on a 72GB UW320 SCSI. A few VM OSes run on another UW320 SCSI drive. The 200GB IDE drive has just data on it.