[Udpcast] No success with imaging XP

I would like to use an external, partitioned 250 GB HD to image 3 separate XP computers each 30 GB in size. How do I do this so that if any one of the 3 computers' HD died, I could immediately copy the image for that computer back to a new HD from the corresponding partition of the external HD so I wouldn't have to go through the laborious setup process of installing several of programs. As I understand it Acronis and Norton Ghost will not allow copying an image to a partitioned external drive - they demand using only one partition on the external drive - thus 1 backup max per external HD. Thanks Paul Creelman