Just convince yourself that your external hard disk is inside the PC, and treat it exactly as you would an internal one. The good ol' way is always having one primary and one Extended with 1 or more Logical volumes in it. But since you are going to encrypt a partition, I would create two primaries + the extended, this way you can easily make the second Primary bootable if needed. I would personally suggest to make a greater number of partitions/logical volumes in the extended, a 995 Gb partition is biggish and any operation you may later need to do on it (defragging/imaging/data recovery , etc.) will take AGES on an external (I presume USB) bus. jaclaz Could you explain the difference between all the partition types. If I do two primaries and one extended which one would be best to use as my encrypted partition? I did discover that having a massive partition is a bad idea. Truecrypt crashed when I playing with it cause the HD is so big. It has USB and ESATA. I specifically got this one cause I know ESATA is way faster than USB. Best way to do this is to use disk management gui inside windows. Start > Run > diskmgmt.msc If your HDD already has a single large partition (i.e. store bought USB drive) you will need to first delete all partitions on the drive. (back up any data first) Right click the blank HDD, create a new 5 GB partition (NTFS should be default selection), then repeat the process to create your second partition. That's it. Pretty simple huh. What partition types do recommend I use? Yep it is . Read here, first result.