BitLocker Drive Encryption (Vista and Windows 7)
http://en.wikipedia.org/wiki/BitLocker_Drive_Encryption
Diskpart
Select Disk 0
Clean
Create Partition Primary Size=50000
Assign Letters=S
Active
Create Partition Primary Size=101000
Assign Letter=C
List Volume
Volume 0 F LRMCFRE_RO_ UDF DVD-ROM 2646 MB H
VOLUME 1 S RAW PARTITION 49 GB H
VOLUME 2 C RAW PARTITION 100 GB H
Exit
Format C: /Y /Q /FS:NTFS
Format S: /Y /Q /FS:NTFS
Exit
ALT F4
Install Now
Disk 0 Partition1 48.8GB 48.7GB Principal
Disk 0 Partition2 100.2GB 100.1GB Principal
(choose Partition2 for Install Now)