NEED HELP with Initial setup / partition of external hard drive

This is my first time in the external hard drive area so please bear with me.

My current computer is Windows XP and my new one is Windows 7.  I have a My Book Essential 1 TB external HD.

My plan is to:

1.  Partition the hard drive in 2 separate areas on the XP machine.  One approx. 100 GB and the other 900 GB.

2.  Backup everything on the XP machine to one partition (approx. 100 GB) using the SmartWare (?) that comes with the drive.

3.  Run the Easy Transfer Wizard to create a file that I can move to the new computer and put that on the smaller partition.

4.  Unplug it from the XP machine and plug it in to the Windows 7 machine.

5.  Use the Easy Transfer to convert and copy the files over.

6.  Use the larger partition for backup on the Windows 7 machine while still having the files from the XP machine on the smaller partition.

My question is can I do this and how???  Have any of you tried this before and ,if so, do you have any tips?

Does anyone have any thoughts on this?

It is possible to format the drive into multiple partitions. However, WD only supports one partition on the drive. SmartWare will also only backup to the first partition that it finds on the external. If you make the first partition 100MB and backup your XP computer to it, the backup will go to that partition. However, if you use SmartWare on your Windows 7 computer, it will backup to this same partition, it will not go to the second partition on the drive.

So, LB_WD, to follow up, I should be able to remove the SmartWare software from the hard drive and use a partition software package to partition it into 2 separate drives.  Then use Image software to create the XP image and put it on the smaller partition.  Then use backup software to backup the Windows 7 drive to the larger partition with the XP image on the smaller one.  Will that work?