I have also a similar problem. I am using Windows System Image Manager (WSIM) tool to create an answer file (or Unattended.xml) file. I did almost what ever I need except the partitioning the hard disk. It provides an option to create and modify partitions. But it takes only the partition size in terms of megabytes (the same was listed in MS's API help page ). Is there any hack where we can specify the partiton size in terms of percentage. The reason is that, I wanted to make use of this answer file at different location and places where the harddisk sizes are not same.
Any help would be appreciated.