If you're not familiar with Microsoft Windows Vista's own disk management tools, don't beat yourself up over it. They're not exactly lying around the desktop in plain sight. But they are worth checking out.
To find Windows Vista's disk-management tools, you need to open the Control Panel, double-click Administrative Tools, double-click Computer Management, look under Storage and finally choose Disk Management. There! That was simple, wasn't it?
Microsoft uses the archetypel user interface that the other packages are emulating. While third-party apps tend to provide more features and options, Vista is no slouch.
To manage a partition, you select it from a list that Computer Management generates, and right-click to view a menu of available processes you can apply. If you instead right-click on the disk name (which is located on the right side of the partition info), you'll find options that will let you manage a new and unformatted partition.
How do you get things done? Sometimes creatively. To check the data integrity of your partition or defragment it, you tackle those tasks by opening Computer, right-clicking on the disk icon you want to look at, selecting the Tools tab, and then choose either Defragmentation or Error Checking.
To split one partition into two, right-click on it, select Shrink Volume and enter the sizes of the partitions you want to create. In relatively short order, you'll find yourself with a formatted partition that represents the original volume you had (diminished in size but with the data intact) and a raw partition that represents the remainder of the disk capacity.
You can turn that raw space into a new volume and then format it for use. If you change your mind, you can right-click your original partition and either extend it or return it to its original size.
Merging the two partitions is slightly more arduous. You need to copy the contents of the second partition to the first, assuming there's room, delete the second partition and then use the Extend option to change the first partition's size. The end result is the same, but with more steps involved.