Rome5

Yes, it's different. You can only have four primary partitions on a drive, but to get around that, for one of those primary partitions, you create an extended partition. The extended partition 'acts' like a primary, but it's different because it can then be divided up into sub-partitions (logical). You want an extended partition to take up the rest of the available space on the drive - 60GB. Then, you break that down into 20GB for root, 1GB for swap, and 39GB for storage or whatever.

[ 100GB XP / primary]
[ 100GB Vista / primary]
[ 60GB / extended --
-- [ 20GB root ]
-- [ 1GB swap ]
-- [ 39Gb storage ]
-- ]


#NOTE: you can break up the remaining 39GB of space into more than one logical partition. Once you do it the first time and get the hang of it, creating partitions becomes pretty easy.