HD active partitions

Dear friends,
I need to clone 3 different HD with already installed and set application programs based on Windows NT (each one=5 GB) to only ONE HD (20 GB)in such way that each of the 3 cloned HD with application software to be accessible and elective when the PC starts.
I suppose this 20 GB HD probably have to be partitioned in 3 active parts.Does anyone has experience in such matter.Please, help me with links and name of the right software for doing such partition.
Thanks in advance